Cross-Platform Release Notes for Cisco IOS Release 12.2SB: Caveats for 12.2(28)SB through 12.2(31)SB14
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Table Of Contents
Caveats for Cisco IOS Release 12.2(28)SB
through 12.2(31)SB14Resolved Caveats—Cisco IOS Release 12.2(31)SB14
Resolved Caveats—Cisco IOS Release 12.2(31)SB13
Resolved Caveats—Cisco IOS Release 12.2(31)SB12
Open Caveats—Cisco IOS Release 12.2(31)SB11
Resolved Caveats—Cisco IOS Release 12.2(31)SB11
Resolved Caveats—Cisco IOS Release 12.2(31)SB10
Resolved Caveats—Cisco IOS Release 12.2(31)SB9
Open Caveats—Cisco IOS Release 12.2(31)SB8
Resolved Caveats—Cisco IOS Release 12.2(31)SB8
Resolved Caveats—Cisco IOS Release 12.2(31)SB7
Resolved Caveats—Cisco IOS Release 12.2(31)SB6
Resolved Caveats—Cisco IOS Release 12.2(31)SB5
Open Caveats—Cisco IOS Release 12.2(31)SB3
Resolved Caveats—Cisco IOS Release 12.2(31)SB3
Open Caveats—Cisco IOS Release 12.2(31)SB2
Resolved Caveats—Cisco IOS Release 12.2(31)SB2
Resolved Caveats—Cisco IOS Release 12.2(28)SB13
Resolved Caveats—Cisco IOS Release 12.2(28)SB12
Open Caveats—Cisco IOS Release 12.2(28)SB11
Resolved Caveats—Cisco IOS Release 12.2(28)SB11
Resolved Caveats—Cisco IOS Release 12.2(28)SB10
Resolved Caveats—Cisco IOS Release 12.2(28)SB9
Resolved Caveats—Cisco IOS Release 12.2(28)SB8
Resolved Caveats—Cisco IOS Release 12.2(28)SB7
Open Caveats—Cisco IOS Release 12.2(28)SB6
Resolved Caveats—Cisco IOS Release 12.2(28)SB6
Resolved Caveats—Cisco IOS Release 12.2(28)SB5
Resolved Caveats—Cisco IOS Release 12.2(28)SB4
Resolved Caveats—Cisco IOS Release 12.2(28)SB3
Resolved Caveats—Cisco IOS Release 12.2(28)SB2
Resolved Caveats—Cisco IOS Release 12.2(28)SB1
Open Caveats—Cisco IOS Release 12.2(28)SB
Cisco IOS Software Documentation Set
Cisco IOS Release 12.2 Documentation Set Contents
Obtaining Documentation and Submitting a Service Request
Caveats for Cisco IOS Release 12.2(28)SB
through 12.2(31)SB14
Caveats
Caveats describe unexpected behavior in Cisco IOS software releases. Severity 1 caveats are the most serious caveats; severity 2 caveats are less serious. Severity 3 caveats are moderate caveats, and only select severity 3 caveats are included in this section.
Because Cisco IOS Release 12.2SB is based on Cisco IOS Release 12.2, many caveats that apply to Cisco IOS Release 12.2 also apply to Cisco IOS Release 12.2SB. For information on severity 1 and 2 caveats in Cisco IOS Release 12.2, see the Caveats for Cisco IOS Release 12.2 document located on Cisco.com.
In this section, the following information is provided for each caveat:
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Symptoms—A description of what is observed when the caveat occurs.
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Note
This section consists of the following subsections:
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Resolved Caveats—Cisco IOS Release 12.2(31)SB14
Cisco IOS Release 12.2(31)SB14 is a rebuild release for Cisco IOS Release 12.2(31)SB. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB14 but may be open in previous Cisco IOS releases.
Miscellaneous
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Symptoms: Using the output-delay router configuration command may affect the rate at which incoming Routing Information Protocol (RIP) updates are processed.
Conditions: To diagnose this situation, look at the output of the show ip socket command and look at the IN column for port 520. The value should remain relatively low (less than 20) if the updates are being serviced correctly.
Workaround: Set the output-delay router configuration command to a smaller value or remove it altogether.
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Symptoms: A multilink interface may stop processing received packets.
Conditions: This symptom is observed on a Cisco 7500 series when Multilink PPP (MLP) is configured and when a lot of traffic is forwarded to the process-switching path.
Workaround: To clear the symptom, move the physical interfaces to a new multilink interface with a new interface number.
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Symptoms: A Cisco router that is configured for Network Address Translation (NAT) may reload unexpectedly because of a software condition.
Conditions: This symptom can occur when the router translates a Lightweight Directory Access Protocol (LDAP) packet. NAT translates the embedded address inside the LDAP packet. This problem is strictly tied to NAT and LDAP only.
Workaround: There is no workaround.
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Symptoms: Some virtual circuit (VC) information is missing in the Simple Network Management Protocol (SNMP) MIB object cAal5VccEntry from the output of the snmpwalk router configuration command. The ATM VCs 0/100, 0/200 and 0/500 exist on the router but are missing in the MIB.
Conditions: This symptom is observed on a Cisco 7513 router that is running a special image of Cisco IOS Release 12.2(15)T5. The symptom may also occur in other releases.
Workaround: Enter the show atm vc privileged EXEC command on the same device to obtain a complete list of all the VCs.
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Symptoms: The output of serial interfaces on a PA-MC-8TE1 may become stuck after several days of proper operation.
Conditions: This symptom is observed on a Cisco 7206VXR that runs Cisco IOS Release 12.3(10a) and that has MLP configured on the serial interfaces of the PA-MC-8TE1.
Temporary Workaround: Perform an OIR of the PA-MC-8TE1 or reload the router until the symptom occurs again.
Further Problem Description: The symptom occurs during normal operation of the router. If many errors occur on the link, the symptom is more likely to occur.
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Symptoms: The show kron schedule command may cause the router to reload.
Conditions: This symptom is observed when Kron is configured with the occurrence scheduled for Sunday.
Workaround: Do not issue the show kron schedule command.
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Symptoms: During switchover following error message appears:
%MFI-3-REDISTMGR: Redistribution Manager: register - null LSD 16.
Conditions: There is no specific condition. A switchover is done with MPLS application enabled.
Workaround: There is no workaround.
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Symptoms: A router may reload unexpectedly when you reconfigure the login block-for command.
Conditions: This symptom is observed happens after a couple of invalid login attempts have occurred and then you reconfigure the login block-for command.
Workaround: There is no workaround.
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Symptoms: Even though the interface is not congested, packets are getting dropped on ATM interfaces.
Conditions: The symptom is observed with Voice Activity Detection (VAD) and the G711 codec.
Workaround: Do not set the vectors and queueing algorithm if it is already set to QUEUE_PER_VC. The drivers are expected to initialize this if the particular driver supports Per-VC queueing.
Further Problem Description: ATM drivers now support Per-VC queueing. It sets the idb->queuing_algorithm to QUEUE_PER_VC. But HQF overwrites this to QUEUE_HQF. In many places, including common code, it checks for the queueing algorithm and does ATM Per-VC specific queueing. But since HQF was setting this wrongly, it goes to a separate code.
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Symptoms: Back-to-back link goes down in POT1E1 and PA on configuring ISIS.
Conditions: This symptom happens only in Cisco IOS Release 12.2SR.
Workaround: There is no workaround.
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Symptoms: The following error messages may be displayed on the active RSP of a Cisco 7500 series:
%IPC-3-ISSU_ERROR: ISSU register peer failed with error code 0 for seat 1010000 %ISSU-3-NOT_FIND_UNDER_ENDPOINT:
Can not find peer uid by transport ERP id(0x1010000) control block under endpoint.Conditions: This symptom is observed on a Cisco 7500 series that runs a crypto image of Cisco IOS Release 12.2SB.
Workaround: There is no workaround. Note that the symptom does not cause any side effects.
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Symptoms: A Cisco router configured for Virtual Private Dialup Network (VPDN) may unexpectedly reload with Bus Error.
Conditions: This symptom was observed on a Cisco7200VXR series router equipped with NPE-G1 processor card running Cisco IOS Release 12.3(14)T3.
Workaround: There is no workaround.
Further Problem Description: The crash was preceded by "SYS-2-INPUT_GETBUF: Bad getbuffer" error messages.
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Symptoms: CDP may not be enabled with snmpset.
Conditions: The symptom is observed when CDP is globally disabled and when the user attempts to enable CDP from SNMP.
Workaround: Enable CDP from CLI.
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Symptoms: On a Cisco router that is configured for Hierarchal Queueing Framework (HQF), the RP may crash and generate an "ALIGN-1-FATAL" error message when the "PC hqf_process_wfq_command" function is accessed.
Conditions: This symptom is observed on a Cisco 7600 series that runs Cisco IOS Release 12.2(18)SXE2 or Release 12.2(18)SXF4 but may also affect other platforms and releases. The symptom occurs on rare occasions after a service policy has been modified on an ATM subinterface or PVC.
Workaround: There is no workaround.
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Symptoms: PIM dense mode interoperability issues are seen with Cisco and third party boxes.
Condition: This symptom is observed when PIM dense mode is in operation. After the multicast forwarder is decided, based on the assert mechanism, a prune is erroneously sent. Multicast stream ceases to flow.
Workaround: There is no workaround.
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Symptoms: The neighbor default-originate command does not function properly when the route map keyword and map-name argument are defined.
Conditions: This symptom is observed when the target route that is specified in the route map is added or removed from the routing table after the BGP session has already been established.
Workaround: Clear and re-establish the BGP neighbor.
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Symptoms: A router hangs on a regular basis producing the following traceback:
%SYS-2-NOTQ: unqueue didn't find 0 in queue 82E19A74
-Process= "<interrupt level>", ipl= 2
-Traceback= 0x80836CE8 0x814DC7F0 0x814EBE5C 0x816DF1F0 0x816DF2A8 0x816DEF74 0x816DE8D4 0x80076750 0x8072CFA0 0x8072D10C 0x803B128C 0x80143E5C 0x801383B4 0x8013AB0C 0x8013D6E0 0x8037DF44Conditions: This symptom is observed on a router that is acting as an EzVPN Client. From the traceback, it seems that the BVI interface is involved in the crash.
Workaround: Disable bridging or HW encryption.
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Symptoms: Tracebacks are seen while applying queueing policy after deleting/creating subinterfaces.
Conditions: Tracebacks are seen while applying queueing policy after deleting/creating subinterfaces.
Workaround: There is no workaround.
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Symptoms: The following error messages may be seen:
%QOS-3-HQFPOOLERR: interface GigabitEthernet0/2: failed to allocate hqf particle %QOS-3-HQFPOOLERR: interface GigabitEthernet0/2: failed to allocate hqf particle %SYS-3-CPUHOG: Task is running for (2004)msecs, more than (2000)msecs (154/17),process = Logger.
-Traceback= 609222CC 60922360 60920BA4 60766C0C 60765CE8 607663F0 60768328 : %SYS-3-CPUHOG: Task is running for (4004)msecs, more than (2000)msecs (290/17),process = Logger.
-Traceback= 609222CC 60922360 60920BA4 60766C0C 60765CE8 607663F0 60768328Conditions: The symptom is observed with a Cisco 7200 series router with NPE- G1 that is running the c7200-g9js-mz.2006-07-24.XNTD image and is loaded with mixed traffic of IPv6 multicast, IPv6 unicast, SBC RTP, and PPPoE.
Workaround: There is no workaround.
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Symptoms: A "%SCHED-3-STUCKMTMR" error message and traceback may be generated during the "SNMP Timers" process.
Conditions: This symptom is observed when there are too many RMON collection events and alarms. The error message and traceback may also be generated when many entries/rows are created in certain MIBs and occur because of simultaneous row creation timeouts.
Workaround: Ensure that there are not too many RMON collection events and alarms or simultaneous row creation timeouts. However, note that the error message and traceback do not have an impact on the functionality of the platform. The messages are just warning messages from the Cisco IOS process scheduler, indicating that the process (in this case the "SNMP Timers" process) is not able to process all the events before the process suspends.
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Symptoms: When dialer interfaces are used in conjunction with Multilink PPP (MLP), a router may crash because of a corrupted program counter.
Conditions: This symptom is observed on a Cisco router when a dialer interface, including interfaces such as ISDN BRI and PRI interfaces, is configured to use MLP and when the queueing mode on the dialer interface is configured for Weighted Fair Queueing (WFQ). Note that WFQ is the default for some types of dialer interfaces.
Workaround: There is no workaround.
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Symptoms: A router may crash when the standby RP does not enter the Hot Standby state.
Conditions: This symptom is observed on a Cisco router that functions in a high availability environment during the boot process of the router.
Workaround: There is no workaround.
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Symptoms: A device crashes with a bus error when the show ip bgp dampening dampened-paths command is used.
Conditions: This symptom is observed when the show ip bgp dampening dampened-paths command is used and the device is at the "More" prompt to continue with remaining output, if the BGP session goes down at that time (for example, receiving a notification) or because of a clear ip bgp command from another vty.
Workaround: There is no workaround.
If dampening is configured, do not run "sh ip bgp neighbors <x.x.x.x> dampened-routes" "sh ip bgp dampening dampened-paths" which can cause this problem
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Symptoms: A spurious access occurs when a serial port adapter is removed via Online Insertion and Removal (OIR).
Conditions: This symptom is observed if one or more serial interfaces on the port adapter are members of a multilink bundle and data traffic is flowing through the bundle when the port adapter is removed. This symptom has been seen on a Cisco 7200 series router, but it is not believed to be platform-specific.
Workaround: Shut down the serial interfaces before removing the port adapter.
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Symptoms: The local BGP MDT prefix may be missing.
Conditions: This symptom is observed on a Cisco router that has the mdt default group-address command enabled under a VRF configuration and occurs after you have entered the clear ip bgp * command.
Workaround: Disable and re-enable the mdt default group-address command.
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Symptoms: The removal of NAT protocol address translation command from the configuration, which refers to the same interface which is used for overloading, will cause a system restart.
Conditions: This symptom occurs assuming that the interface used for overloading/PAT has an IP address:
ip nat inside source route-map <name> interface Ethernet1/0 overload
ip nat inside source static tcp <addr> <lport> interface Ethernet1/0 <gport>
no ip nat inside source static tcp <addr> <lport> interface Ethernet1/0 <gport>This is applicable for all Cisco IOS 12.2S based releases.
Workaround: Do not remove the PAT configuration once applied.
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Symptoms: A PE router crashes when ATM PVC is created on the other end CE.
Conditions: This symptom occurs when an ethernet sub-interface bound to an ATM VC through a connect command is deleted, ATM VC gets improperly removed leading to stray VCD in the PA. When traffic passes through the stray ATM VC, it crashes.
Workaround: Do not remove ethernet subinterface when it is bound to an ATM VC through a connect command.
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Symptoms: Under extremely unusual conditions, a multilink-group interface may not start PPP, after two or more serial links have negotiated PPP and joined that bundle interface, creating a bundle. Inspection of the output from the show ppp multilink command will show that the bundle exists and has active member links. However, inspection of output from show interface and show ppp interface will reveal that the bundle interface is in a "Line-Protocol Down" state, and further indicates that the bundle interface is in "LCP Negotiating" phase.
Conditions: This can occur if two or more PPP serial links are assigned to a common multilink-group interface, and the links come up and negotiate PPP in near perfect simultaneity, but the links do not receive the exact same remote endpoint identification credentials (these being the PPP Multilink Endpoint Discriminator and/or PPP Authenticated username) on all the links. Note that this situation should never normally arise, at it could not itself occur except as a result of some other error (for example a cabling error, a misconfiguration at one end or the other, or an operational error with the remote system). It is implicit in being assigned to a single group interface that all links in the set will be providing identical identification information.
Workaround: Any sequence which resets the bundle interface will generally clear the condition. For example, clear interface Multilink10.
Further Problem Description: This situation occurs if a link comes up and starts the formation of a bundle, and then a second link comes up - with conflicting identification information - in the window of time between when the first link starts the formation of the bundle and when that formation can be completed. Also note that this is specific to the use of static bundle interfaces (multilink group interfaces), and not an issue when dynamic (virtual-access) interfaces are used for the bundles.
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Symptoms: A BGP router may not send the default route to its neighbor.
Conditions: This symptom is observed when the neighbor default-originate command is conditionally configured with a route map and when the matching route is installed into the RIB by BGP itself.
Impacts: May impact traffic forwarding.
Workaround: There is no workaround.
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Symptoms: Invalid updates to the system clock are allowed on the Cisco IOS command line interface (CLI).
Conditions: The symptoms are observed when a user attempts to configure the set end of summer-time earlier than the start of summer-time:
Router(config)#clock summer-time PDT date 11 mar 2007 2:00 ?
<1-31> Date to end
MONTH Month to end
Router(config)#$r-time PDT date 11 mar 2007 2:00 11 march 2007 00:00 60Workaround: Do not pass invalid arguments to the clock summer- time command on the Cisco IOS CLI.
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Symptoms: An ATM interface loses its assigned IP address if the interface is gracefully stopped/started.
Condition: This symptom is observed in Cisco IOS Release 12.4(17).
Workaround: Reconfigure the interface.
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Symptoms: There may be a CPU HOG due to "Syslog Traps" message seen on a device.
Conditions: The symptom is observed when a large number of interfaces are flapping.
Workaround: Disable syslog traps. Use interface level link trap for capturing link up/down notifications.
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Symptoms: Configuring a command with the string "do" inside a sub-mode may cause unexpected behavior.
There is known issue that using the PVC names ending with "do" lead to refusing the command as not valid. The error message "% Invalid input detected at '^' marker." will be displayed if the command is executed in sub-mode. If it is executed in ATM mode, there will be no error reported, but the pvc will be removed from configuration after reload.
Conditions: The symptom is observed when using "do" as shorthand for "domain," for example in ipe domain CLI.
Workaround: Do not use "do" keyword as shorthand in commands inside a sub- mode.
Related to ATM PVC names: do not use PVC names ending with "do".
Further Problem Description: Commands starting with "do" will be interpreted as exec commands.
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Symptoms: Using scp to copy files from disk to SSH server is extremely slow. It takes more than 2 minutes to get the prompt back after launching the command to copy a small file.
Conditions: This has been seen on a Cisco 7600 router running Cisco IOS Release 12.2(33)SRA4 or Cisco IOS Release 12.2(33)SRB.
Workaround: Use another form of copy.
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Symptoms: With bidirectional multicast traffic, a router that is running Cisco IOS Releases 12.2(33)SB, 12.2(31)SB3, 12.2(28)SB7, or later versions may stop forwarding all traffic, or even crash. Ping/ARP fails from adjacent routers as all packets are dropped.
Conditions: This symptom occurs when any event that causes multicast adjacency to be removed (temporarily) from PXF, causing packets to be punted to RP. Some examples are:
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Workaround: There is no workaround.
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Symptoms: Packets are punted when bidirectional multicast traffic is sent in an Multicast VPN (MVPN) network. As a result, the router may experience high CPU utilization and LDP and OSPF neighborships may go down.
Conditions: The symptoms occur when single MVPNs are configured and where traffic is sent from a single MVPN customer. It mostly occurs with bidirectional traffic
Workaround: As the behavior is inconsistent, no complete workaround is available.
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Symptoms: Several features within Cisco IOS software are affected by a crafted UDP packet vulnerability. If any of the affected features are enabled, a successful attack will result in a blocked input queue on the inbound interface. Only crafted UDP packets destined for the device could result in the interface being blocked, transit traffic will not block the interface.
Cisco has released free software updates that address this vulnerability.
Workarounds that mitigate this vulnerability are available in the workarounds section of the advisory. This advisory is posted at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20090325-udp.shtml.
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Symptoms: Under a high load of multicast traffic, a Cisco router may unexpectedly reload due to a CPU vector 300 or bus error.
Conditions: This symptom has been observed only in environments where more than 10 tunnels have been configured on the same device using multicast over these tunnels.
Workaround: There is no workaround.
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Symptoms: When the no ip portbundle command is issued, the portbundle feature is removed unconditionally without checking if the portbundle is assigned to a session and is in use.
Conditions: This symptom is observed when the no ip portbundle command is issued.
Workaround: Before unconfiguring portbundle, check if it is assigned to a subscriber session. If it is assigned, display a message and do not unconfigure portbundle.
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Symptoms: Router crashed while reconfiguring a three-level policy.
Conditions: Seen on a Cisco 7200 router.
Workaround: There is no workaround.
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A vulnerability in the handling of IP sockets can cause devices to be vulnerable to a denial of service attack when any of several features of Cisco IOS software are enabled. A sequence of specially crafted TCP/IP packets could cause any of the following results:
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Workarounds that mitigate this vulnerability are available in the "workarounds" section of the advisory. The advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090325-ip.shtml
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Symptoms: Platforms that are acting as LACs may experience a reload in rare occasions due to variables not being initialized under this rare circumstance.
Conditions: This crash can only occur only if the device is configured to act as a LAC, initiating L2TP tunnels to LNS devices.
Workaround: There is no workaround.
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Symptoms: Multicast tunnel not coming up after RPM change. A misconfiguration with overlapping networks causes the join to be rejected. This can be seen on the PIM neighbor list.
Conditions: There is a problem related to one of the hub card in rpm-xf.10 in forwarding PIM traffic from 2 PEs ( rpm-xf.13 & rpm-xf.11 ). After RP migration from AVICI to CRS we found that tunnels from PE in slot 13 were not coming up. PE in slot 13 was in consistently in registering mode. PE was not coming out of registering mode which was preventing the tunnels from coming up. For PE to come out of registering mode S,G state should be built from new RP down to PE. At this stage the CRS (RP) showed that S,G tree was establish at the RP. S,G tree was OK all the way down from CRS to the last hop (P in slot 10) connecting to the slot 13 PE. The P router in slot 10, which is directly connected to PE, showed that S,G state was established and PE facing interface was in OIL. But there were couple of discrepancies on the P in slot 10. There were no flags set on this P for the mroute of PE. In addition, we found that PE was not receiving any PIM traffic from the P in slot 10. This led to suspicion that although the P showed the correct S,G and OIL but is still not able to forward traffic to the PE. And this could be the reason for PE to remain in registering mode hence preventing the tunnels from coming up.
Workaround: Remove the following configurations:
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Symptoms: Traceback seen while doing Telnet with SSH enabled.
Conditions: Occurs when SSH is enabled on a Cisco 7200 router.
Workaround: There is no workaround.
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Symptoms: A router may reset due to a bus error when removing the legacy traffic shaping (traffic-shape rate XXX) from the interface with the presence of traffic.
Conditions: Having both the legacy traffic-shaping (traffic-shape rate XXX) and MQC shaping (through policy-map) configured on the interface and trying to remove either of them will cause this issue to occur.
Workaround: Avoid making changes to the traffic-shaping configured on the interface with traffic crossing the interface.
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Symptoms: 1. Although a shaping policy is applied to VAccess sessions, the shaping function is not bounding traffic to a specific rate. 2. The show interface command for the ATM interface shows "class-based queueing" instead of "per-vc queueing".
Conditions: The symptoms are observed under the following conditions:
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Workaround: Clear and re-establish all sessions.
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Symptoms: A Cisco 10000 series router may run out of PXF-memory and end up in a state not being able to create new PPPoE sessions.
Conditions: This symptom is seen during an aggressive churning test with lawful intercept enabled on all sessions via Radius.
Workaround: There is no workaround.
Further Problem Description: This may show up on live systems just very slowly, depending on LI-activity. The leak can be monitored by following the output of the sh pxf cpu cef mem | i Mac|write|^Type|^C10 command.
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Symptoms: The router may exhibit the following symptoms when classification based on FR-DE and IP TOS is turned on:
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Conditions: These symptoms are seen in a Cisco 7300 or Cisco 10000 router that is running Cisco IOS Release 12.2(33)SB. The symptoms are not seen in a Cisco 7200 router.
Workaround: Detach and reattach the policy-map to the interface.
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Symptoms: A Cisco 7304 router with NSE100 may punt all MPLS-to-IP traffic from PXF to RP when egress interface is a VRF GRE tunnel interface.
Conditions: The issue affects Cisco IOS Releases 12.2(28)SB and 12.2(31)SB.
Workaround: There is no workaround.
Further Problem Description: The issue is not seen with Cisco IOS Release 12.2 (25)S.
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Symptoms: A router may show error messages when applying/using a policy-map on ATM, having set cos cos configured.
Conditions: This symptom appears when the policy gets applied during PPPoE session establishment.
Workaround: The command is not supported on ATM interfaces and correcting the configuration prevents the error-messages for new VCs. Any VCs previously used with it already fail to get the right policy applied. To correct this, remove the pvc-in-range and reapply it with the previous configuration.
Further Problem Description: This defect just moves the error-message to a warning. The function itself will stay unsupported on ATM-interfaces. After correcting the configuration tracebacks left over which required the system to reload. No impact seen by the tracebacks.
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Symptoms: A router reloads.
Conditions: This symptom happens when many PPPoEoA sessions are created over AutoVCs.
Workaround: Increase the VeryBig buffer pool so that there are no more misses, creates and trims. For example, use the following statements:
buffers verybig permanent 7000 buffers verybig max-free 7000
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Symptoms: The no ip proxy-arp command that is configured under ISG enabled interface is not working.
Conditions: This symptom is observed on the ethernet interface, where an ip subscriber command is configured. Same interface allows disabling IP Proxy ARP with the no ip proxy-arp command, but the command is ignored.
Workaround: There is no workaround.
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Symptoms: The following error messages may appear in the log file multiple times:
%ARP-3-ARPINT: ARP table accessed at interrupt level 1,
-Traceback= 0x61013944 0x60B61F80 0x60B5A2A4 0x6019DDAC 0x600FA37C 0x600FCC6C Because the message is generated frequently, the log file may fill up too soon.Conditions: The symptom is observed because an IOS component is accessing the arp cache table in the interrupt context, which against the design of the IOS module. The error message indicates that the software is in danger of causing the router to crash.
Workaround: There is no workaround.
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Symptoms: A router crashes with QoS while doing OIR on PA-A3-OC3MM.
Conditions: This symptom is observed when a router crashes with QoS while doing OIR on PA-A3-OC3MM with continuous traffic flow.
Workaround: The crash is not seen in following cases:
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Symptoms: The ESR-HH-1GE card on a Cisco 10000 router may crash with the following message:
"%PXF_NICKEL-2-IB_ERR_SPR: IB Stuck Pause Request Error in slot X/Y"Conditions: The crash is seen on a Cisco 10000 platform that is running Cisco IOS Release 12.2(31)SBX. Previous Cisco IOS versions are potentially affected. Some known conditions that trigger this error are:
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Workaround: There is no workaround.
Further Problem Description: The "IB_ERR_SPR" indicates that the egress data path of the LC is stuck, and the only way to recover the path is to reset the LC. In most of the conditions explained above, the LC was only stuck for few seconds, and in those cases, the LC was unnecessarily reset. In this fix the IB_ERR_SPR handling is improved to avoid such LC resets.
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Symptoms: In Cisco IOS software that is running the Border Gateway Protocol (BGP), the router may reload if BGP show commands are executed while the BGP configuration is being removed.
Conditions: This problem may happen only if the BGP show command is started and suspended by auto-more before the BGP-related configuration is removed, and if the BGP show command is continued (for example by pressing the SPACE bar) after the configuration has been removed. This bug affects BGP show commands related to VPNv4 address family. In each case the problem only happens if the deconfiguration removes objects that are being utilized by the show command. Removing unrelated BGP configuration has no effect.
This bug is specific to MPLS-VPN scenarios (CSCsj22187 fixes this issue for other address-families).
Workaround: Terminate any paused BGP show commands before beginning operations to remove BGP-related configuration. Pressing "q" to abort suspended show commands, rather SPACE to continue them, may avoid problems in some scenarios.
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Symptoms: A router may crash after displaying errors similar to:
%QOS-3-ATLEAST_ONE_FAILOVER_ERR: Fail-over of dynamic interface failed
Address Error (load or instruction fetch) exception, CPU signal 10, PC = 0x61A9F260Conditions: The symptom is observed on a router that is running Cisco IOS Release 12.2(31)SB11.
Workaround: There is no workaround.
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Symptoms: ATM VC are not getting enough traffic through due to VC flow control when no burst value is configured for the VC.
Conditions: The symptom is observed when no burst value is configured for the VC.
Workaround: Configure a lower burst value.
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Symptoms: Router bus error crash on invalid address:
System returned to ROM by bus error at PC 0x608BB8A4, address 0xC6000E8E
Address Error (load or instruction fetch) exception, CPU signal 10, PC = 0x608BB8A4
-Traceback= 608BB8A4 608EE2F4 600132B8 605B2140 60A26C20 605B1C54 605B2FB4Conditions: Occurred on a Cisco 7200 running Cisco IOS Release 12.2(28)SB6.
Workaround: There is no workaround.
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Symptoms: An interface is congested. A QoS policy-map is applied to the interface such that one of the traffic-classes receives only infrequent packets. That traffic class is seen to have higher than expected latency. If steady traffic is sent through the same traffic class, then latency is as expected and bandwidth is seen to be shared between traffic classes as per their relative bandwidth guarantees.
Conditions: The symptoms are observed on any interface, but is most obvious with low speed interfaces such as ATM PVCs with 256k or less bandwidth.
Workaround: If the traffic class with the infrequent traffic in configured with priority, then latency will be minimized. For ATM on NPEG100 specifically, adding an extra traffic-class with a priority command will put the driver in low-latency mode which will reduce latency for the traffic class with infrequent traffic. The extra traffic class does not need to match any traffic.
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Symptoms: An ATM interface that is configured with a large number of PVCs may exhibit PVC provisioning problems after repeated interface flaps. The VCC count on the ATM interface would increase by a random number once after each flap.
Conditions: This symptom is observed on a dual PRE2 system that is running Cisco IOS Release .2(31)SB12 code and operating in SSO mode.
Workaround: Router reload or PRE cutover.
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Symptoms: Creating a sub-interface may occasionally cause a traceback
Conditions: This may happen when configuring an ATM or SONET sub-interface.
Workaround: There is no workaround.
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Symptoms: There is a leak in system resources (SHDB).
Conditions: This symptom occurs when a large number of PPPoE sessions are churned.
Workaround: There is no workaround.
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Symptoms: The following error message is displayed on the router console during initialization:
"% NBAR Error: hwidb could not found"
Conditions: This symptom may happen when the configuration has QoS policy maps attached to user sessions.
Workaround: There is no workaround.
Further Problem Description: It s a benign diagnostic message which does not imply any problem on the router and can be ignored.
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Symptoms: Traceback is seen while running FRF12.
Conditions: The symptom is observed during post-router check. The issue is seen with PRE-2.
Workaround: There is no workaround.
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Symptoms: Spurious memory access or crash is seen with fall-over configuration.
Conditions: The spurious memory access is seen when fall-over is configured under a peer-session template.
Workaround: There is no workaround.
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Symptoms: BGP does not generate updates for certain peers.
Conditions: BGP peers show a neighbor version of 0 and their update groups as converged. Out queues for BGP peers are not getting flushed if they have connection resets.
Workaround: There is no workaround other than entering the clear ip bgp * command.
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Cisco IOS software contains a vulnerability in multiple features that could allow an attacker to cause a denial of service (DoS) condition on the affected device. A sequence of specially crafted TCP packets can cause the vulnerable device to reload.
Cisco has released free software updates that address this vulnerability.
Several mitigation strategies are outlined in the workarounds section of this advisory.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090325-tcp.shtml
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Symptoms: Router crashes when service policy is applied while traffic is flowing.
Conditions: Occurs on a Cisco 7200 after applying policy map on PVC with traffic.
Workaround: Stop traffic before applying service policy map.
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Symptoms: Packets marked with dscp af31 are incorrectly classified as dscp2.
Conditions: This issue has been observed on a Cisco 7300 with NSE-100 that is running Cisco IOS Release 12.2(28)SB9. Also seen in a repro that is using Cisco IOS Releases 12.2(28)SB9, 12.2(28)SB12 and 12.2(33)SB1.
The QoS configuration has 3 hierarchies.
Workaround: There is no workaround.
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Symptoms: In a Multicast NAT setup when the traffic is flowing, half of the packets may be dropped with reason given as "Multicast Adjacency Drop".
Conditions: This symptom is observed on Cisco 7304 NSE 100 platform where Multicast NAT is configured and PXF is enabled. Multicast NAT is not supported when PXF support is enabled so all the Multicast NAT traffic is being punted to RP. The punted Multicast packets are destined to be rate limited to 500pps when they pass through RP. In this case, instead of rate limiting to 500pps, exactly half of the packets were dropped with the reason given as "Multicast Adjacency Drop" and half of them processed correctly (reason: "Multicast Drop Recovery Punt").
Workaround: Disable PXF using "no ip pxf" in configure mode.
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Symptoms: The router crash when the default pppoe enable command is entered.
Conditions: Occurs with 4094 PPPoE sessions active. When the above command is used to disable PPPoE under Ethernet subinterface, the router crashes.
Workaround: There is no workaround.
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Symptoms: After deleting and configuring back some timeslots for an ESR-4OC3- CHSTM1 card, the PRE3 of a Cisco 10000 series router crashes for a TLB exception. The same issue happens three minutes later when the same steps are applied to the backup PRE.
Conditions: This symptom is observed after an upgrade to PRE3 and Cisco IOS Release 12.2(33)SB.
Workaround: There is no workaround.
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Symptoms: On a 8e3ds3 line card with L2 transport VC, changing the mode from ADM to PLCP and then performing an SSO causes CDVT that is attached to the L2 Transport VC to reset the standby continuously. CDVT is not supported for L2 Transport VC.
Conditions: This symptom is observed on a Cisco 10000 series router with an 8e3ds3 line card.
Workaround: There is no workaround.
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Symptoms: The error message "Must remove traffic-shape configuration first" is seen, and QoS policy is not getting attached.
Conditions: This symptom is seen when unable to attach a queueing policy-map ("bandwidth" configured) through Frame-relay (FR) map-class to a FR-DLCI interface with FRTS enabled.
Workaround: There is no workaround.
Further Problem Description: This has a major functional impact as the QoS- Policy is not getting attached.
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Symptoms: A router hangs for a couple of minutes, then crashes anytime the clear ip bgp neighbor x.x.x in command is issued.
Conditions: This symptom occurs when a router crashes when the clear ip bgp neighbor x.x.x.x soft in command is issued when the following commands are configured for that neighbor (without route-map):
1.
2.
3.
If any one of the commands is not configured, then the router will not crash.
Workaround: Configure route-map instead of filter-list for inbound direction. For example:
"neighbor x.x.x.x filter-list 1 in" replace with "neighbor x.x.x.x route-mapname in"
where,
route-mapname permit 10 match as-path 1•
Symptoms: A PRE-3 that is running Cisco IOS Release 12.2(31)SB code may encounter a Redzone overrun memory corruption crash.
Conditions: Unknown at this time.
Workaround: Turn off Auto IP SLA MPLS by entering the auto ip sla mpls reset command.
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Symptoms: If the startup configuration includes a boot host TFTP command that calls for a file that contains something other than interfaces, the PRE (the primary or the standby) crashes, and the remote configuration file does not make it to the active configuration.
Conditions: The symptom is observed when the startup configuration includes a boot host TFTP command that calls for a file that contains something other than interfaces. If the remote configuration file consists of only interfaces (no matter how many), everything works as expected. This problem is seen in both Cisco IOS Release 12.2(31)SB13 and Release 12.2(33)SB2.
Workaround: Do not have this option configured.
Further Problem Description: Stack degradation or a CPU hog message might also appear on the screen.
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Symptoms: A router may crash due to bus error caused by an illegal access to a low memory address.
Conditions: This happens when a service-policy is applied to an interface.
Workaround: Remove "ip cef distributed" from the configuration.
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Symptoms: VPDN redirect functionality does not work.
Conditions: Basic functionality is broken. No special condition is required.
Workaround: There is no workaround.
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Symptoms: Route-reflector may fail to send withdraw for some prefixes.
Conditions: The symptom is observed when there are PE routers in the same update group. One PE sends a route refresh message to the RR and the other PE sends a withdraw message for multiple routes.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series router may crash every several minutes.
Conditions: The symptom is observed with a Cisco 10000 series router that is running Cisco IOS Release 12.2(31)SB13.
Workaround: Use Cisco IOS Release 12.2(31)SB11.
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Symptoms: Data-Link Switching (DLSw) connection may get stuck in PCONN_WT state when transitioning from two connections to a single connection if the peer closes with a FIN instead of RST. This will prevent the DLSw peers from communicating.
Conditions: The symptom is observed with Cisco IOS Release 12.2(31)SB, and with a peer router capable of a single DLSw TCP connection that attempts to close one of the two connections with a FIN.
Workaround: IP addresses of the DLSw peers can be arranged so that the higher IP address closes first. The IOS peer should initiate the close.
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Symptoms: A Cisco 10008 router may fail to intercept packets for static subnets.
Conditions: The symptom is observed on a Cisco 10008 router with a PRE-2/3 routing engine that is running Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround.
Further Problem Description: Packets are not intercepted because the lawful intercept security ACL does not get applied. This issue is not seen in Cisco IOS Release 12.2(33)SB and dynamic prefixes are intercepted correctly.
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Symptoms: The VRRP state machine transitions into the "Master" state even if the interface is shut down.
Conditions: The symptom is observed only when the interface is configured with "vrrp <group> timers learn", which triggers the state machine to leave the INIT state.
Workaround: As long as timer learning is not configured the problem will not occur. However, if timer learning is required, the command may be entered and the interface can then be configured with "no shut" and then "shut". The VRRP state machine will now return to the correct "INIT" state.
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Symptoms: A Cisco 7300 series router with an NSE-150 may hang with a %SYS-2- NOTQ error message while responding to traceroute messages.
Conditions: The symptoms are observed with a Cisco 7300 series router with an NSE-150. The router must receive traceroute packets on a port-channel main interface.
Workaround: There is no workaround.
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Symptoms: NPE-G1 is crashing with "pppoe_sss_holdq_enqueue" as one of the last functions.
Conditions: Unknown.
Workaround: Entering the deb pppoe error command will stop the crashing.
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Symptoms: DS3ATM police does not behave as expected when we change the mode of the DS3ATM card.
Conditions: The symptom is observed when DS3ATM is in non-default mode, and the output service policy is at the main interface.
Workaround: There is no workaround.
Further Problem Description: When the card is in PLCP mode actual bandwidth should be 40700 but police is using 44200 since there is no change in the queue bandwidth after mode change.
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Symptoms: The M(andatory)-Bit is not set in Random Vector AVP, which is a must according to RFC2661.
Condition: This symptom is observed with Egress ICCN packet with Random Vector AVP during session establishment.
Workaround: There is no workaround.
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Symptoms: An LI tap remains "Operational" even after tap removal.
Conditions: The symptom is observed on a Cisco 10008 router with PRE-2/3 that is running Cisco IOS Release 12.2(31)SB and Release 12.2(33)SB.
Workaround: Reload of the router removes the stale tap.
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Multiple Cisco products are affected by denial of service (DoS) vulnerabilities that manipulate the state of Transmission Control Protocol (TCP) connections. By manipulating the state of a TCP connection, an attacker could force the TCP connection to remain in a long-lived state, possibly indefinitely. If enough TCP connections are forced into a long-lived or indefinite state, resources on a system under attack may be consumed, preventing new TCP connections from being accepted. In some cases, a system reboot may be necessary to recover normal system operation. To exploit these vulnerabilities, an attacker must be able to complete a TCP three-way handshake with a vulnerable system.
In addition to these vulnerabilities, Cisco Nexus 5000 devices contain a TCP DoS vulnerability that may result in a system crash. This additional vulnerability was found as a result of testing the TCP state manipulation vulnerabilities.
Cisco has released free software updates for download from the Cisco website that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090908-tcp24.shtml.
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Symptoms: A Cisco 10000 series router with dual PRE3s or PRE4s may hang.
Conditions: The PRE-A will first observe the following error:
%FILESYS-5-CFLASH: Compact flash card removed from peer PRE (PRE slot B), slot0The PRE-B console will repeatedly show the following errors:
%SYS-3-CPUHOG: Task is running for (2000)msecs, more than (2000)msecs (0/0),process = Flash Card Monitor.
%SYS-3-CPUHOG: Task is running for (2000)msecs, more than (2000)msecs (0/0),process = Standby service handler.Workaround: There is no workaround.
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Symptoms: BGP updates may not be sent out.
Conditions: The symptom is observed when neighbors are flapped in a large- scale scenario.
Workaround: There is no workaround.
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Symptoms: Per-session QoS on virtual-access interfaces, is seen on a LNS that terminates PPPoE sessions.
The shaper in the parent policy-map is not working. There is no backpressure, and the QoS in the child policy-map never starts.
Conditions: The shaper has inconsistent behavior, may work for some sessions and not for others.
Workaround: There is no workaround.
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Symptoms: Packets are getting tapped into one MD when multiple MDs have been configured.
Conditions: The symptom is observed when both tap entries are in the same ACL.
Workaround: There is no workaround.
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Symptoms: Clearing the SSH sessions from a VTY session may cause the router to crash.
Conditions: The symptom is observed when a Cisco 7300 series router is configured for SSH and then an SSH session is connected. If the SSH session is cleared every two seconds using a script, the symptom is observed.
Workaround: There is no workaround.
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Symptoms: "Circuit-id-tag" and "remote-id-tag" attributes may be duplicated in packets sent to the RADIUS server.
Conditions: The symptom is observed with Cisco IOS Release 12.2(31)SB13.
Workaround: Use Cisco IOS Release 12.2(31)SB14.
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Symptoms: A router may crash when doing an OIR of a PA-CC card with traffic passing through the interface in PA-CC.
Conditions: The symptom is observed with a Cisco 7300 HA system. An OIR of a PA-CC card after switchover might cause this issue.
Workaround: There is no workaround.
Further Problem Description: This is due to a race condition between the IPC packet processing of PA-CC and an OIR of the PA-CC card.
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Symptoms: 0.0.0.0 binding with a 0 minimum lease gets created and subsequently removed on the DHCP unnumbered relay.
Conditions: This symptom is observed when DHCP client sends a DHCPINFORM with ciaddr set to its address, but giaddr is empty. Relay fills giaddr with its IP address and the server replies to giaddr. Since the DHCPACK is in response to DHCPINFOM, lease-time option is absent. Relay receives the DHCPACK and tries to process it normally leading to the route addition.
Workaround: There is no workaround.
Additional Information: This behavior can indirectly have a negative impact on the system by triggering other applications to be called because the routing table change is triggered by such DHCP request. Examining "debug ip routing" for 0.0.0.0/32 reveals 0.0.0.0/32 route flapping.
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Symptoms: Line protocol of many interfaces in the 24che1t1 card may go down.
Conditions: The symptom is observed when the line card is reset or coming up when the timeslots of any one of the channels are changed.
Workaround: A further card reset will bring you out of the situation.
Further Problem Description: Encapsulations can be any (HDLC/Frame relay).
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Symptoms: A router may reload randomly following an upgrade to Cisco IOS Release 12.2(31)SB13.
Conditions: The symptom is observed under normal use with the following routers: Cisco 7201, 7301 and 7206 (with NPE-300).
Workaround: There is no workaround.
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Symptoms: "MTU exceeded punt" occurs in an mVPN circuit when traffic is flowing.
Conditions: the router should have more than 255 interfaces (seen via "show pxf interface".)
Workaround: There is no workaround.
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Symptoms: The PRE4 standby RP may get stuck in "in progress to standby hot" mode.
Conditions: The symptom is observed after an RP switchover. The standby RP becomes stuck in an "in progress to standby hot" state until the RF client times out and the active RP resets the standby RP again.
Workaround: There is no workaround.
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Symptoms: In an ISG setup, the gigaword may be incremented randomly by 1 in each accounting update.
Conditions: The symptom is observed with Cisco IOS Release 12.2(31)SB12a. The following radius output shows the issue:
DEBUG: Packet dump:
Acct-Output-Packets = 43118
Acct-Input-Gigawords = 0
Acct-Output-Gigawords = 83
Acct-Input-Octets = 4265182
Acct-Output-Octets = 41795579
DEBUG: Packet dump:
Acct-Output-Packets = 43172
Acct-Input-Gigawords = 0
Acct-Output-Gigawords = 84
Acct-Input-Octets = 4266910
Acct-Output-Octets = 41795147The output shows about 54 packets incremented by 1 gigaword (4 GB of data) within about a 15 minute timeframe.
Workaround: Get the radius server to detect the increment of 1 gigaword after 15 minutes and to discard the previous accounting records.
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Symptoms: A router configured with BGP and VPN import may crash.
Conditions: This is a hard to hit race condition. BGP imports a path from VRF-A to VRF-B. The following steps have to take place in exactly this order for the crash to occur:
1.
2.
3.
Step 3 will result in the crash. If, before step 3, the next-hop re-evaluation manages to process the net in VRF-B then it will clear the bestpath and there will be no crash. If, before step 3, the import code gets a chance to process the net it will clean-up the imported path from VRF-B and then there will be no crash.
Workaround: There is no workaround.
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Symptoms: When manipulating ATM VCs, some traceback or a crash may be observed.
Conditions: The symptoms are observed when LAC and LNS are configured to send Tunnel-Start, Tunnel-Link-Start, Tunnel-Stop and Tunnel-Link-Stop accounting records.
Workaround: There is no workaround.
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Symptoms: The VPDN user does not take LNS-assigned IP addresses when using the DHCP pool.
Conditions: The symptom is observed whenever the DHCP server is unavailable or when the DHCP pool is exhausted.
Workaround: There is no workaround.
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Symptoms: A Cisco 7304 NSE-100 router may crash while unconfiguring the MFR interface.
Conditions: The symptom is observed with a Cisco 7304 router with an NSE-100 and when configuring the MFR interface.
Workaround: Avoid configuring MFR with the Cisco 7304 platform.
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Symptoms: Traffic may not pass through the PA-MC-8TE1+ port adapter.
Conditions: The symptom is observed if the PA-MC-8TE1+ is a member of a multilink bundle or if it is configured with MPLS.
Workaround: There is no workaround.
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Symptoms: A router may crash when removing a three-level hierarchical policy.
Conditions: The symptom is observed with a Cisco 7300 series router with an NSE-150.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB13
Cisco IOS Release 12.2(31)SB13 is a rebuild release for Cisco IOS Release 12.2(31)SB. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB13 but may be open in previous Cisco IOS releases.
Basic System Services
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Symptoms: A router may hang when you enter the show running-config command.
Conditions: This symptom is observed on a Cisco 7200 series but appears to be platform-independent.
Workaround: Do not enter the show running-config command.
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Symptoms: When RIP is enabled and disabled successively 50 to 60 times in a row, the router reloads unexpectedly during the "RIP managed timer" process.
Conditions: This symptom is observed on a Cisco router that has 15,000 learned RIP prefixes. However, note that RIP does not properly scale beyond about 5000 routes on a high-end router.
Workaround: Do not enable and disable RIP successively 50 to 60 times in a row.
First Alternate Workaround: Limit the number of RIP prefixes to 5000 or less.
Second Alternate Workaround: Before RIP is disabled, for example through the no router rip command, remove the network entries under the router rip command.
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Symptoms: Type of Service (ToS) reflected in a L2TP header is not working in Cisco IOS interim Release 12.4(10.8)T2 after configuring the ip tos reflect command on L2TP.
Conditions: This symptom has been observed with Cisco IOS interim Release 12.4 (10.8)T2.
Workaround: There is no workaround.
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Symptoms: A TCB related crash may be seen.
Conditions: There are no specific conditions.
Workaround: There is no workaround.
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Symptoms: The configuration of a deleted subinterface may show up on a new subinterface and may cause a traffic outage.
Conditions: This symptom is observed on a Cisco router that has IP interface commands enabled when a script adds and deletes ATM subinterfaces on a regular basis.
Workaround: Verify the subinterface configuration. When the configuration of a subinterface cannot be deleted, delete the subinterface, and then create a dummy subinterface that will pull the configuration that could not be deleted. Then recreate the first subinterface with a new configuration.
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Symptoms: The command to do a warm upgrade results in a warm reboot.
Conditions: This symptom occurs if a warm upgrade is executed. It will result in a warm reboot, provided the warm reboot is enabled. Ideally it should load the new image. In case the warm reboot is not configured, the system will return to the ROMMON with an error message.
Workaround: There is no workaround.
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Symptoms: Memory corruption, possibly leading to a crash or other undesired behavior, can occur when the no default-information originate command is entered in router RIP configuration mode.
Conditions: This symptom occurs only if both the RIP routing protocol and the OSPF routing protocol are configured on a router.
Workaround: There is no workaround.
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Symptoms: On PPP links that do not support duplicate address detection (DAD), the interface up state can be signaled too early, for example before the interface is actually up. As a result, OSPFv3 neighbor relationship is not established.
Conditions: Any interface that does not support DAD could signal link local up before the interface is up.
Workaround: There is no workaround.
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Symptoms: Memory corruption occurs when a "| include" is used with a CLI command. An already in-use block gets freed and causes this corruption.
Conditions: This symptom can happen with any usage when a "| include" is used with a CLI command. It was found using a script for IPSec that resulted in "Crash on OIR of IPSec SLC module."
Workaround: There is no work around. It is a programming defect.
Further Problem Description: It is a rare corner case memory corruption when a block gets freed even when it is in use. It is caught by a script under stress testing conditions which results in such a rare condition.
While using CLI and "| include" it is rare to get such a corruption. If it happens, it will lead to box reload.
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Symptoms: The neighbor default-originate command does not function properly when the route map keyword and map-name argument are defined.
Conditions: This symptom is observed when the target route that is specified in the route map is added or removed from the routing table after the BGP session has already been established.
Workaround: Clear and re-establish the BGP neighbor.
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Symptoms: When a GRE tunnel is routed over an MPLS cloud, process-switched packets that are destined for the remote end of the GRE tunnel are sent unlabeled.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2S or a release that is based on Release 12.2S when the router functions as a PE router that has a GRE tunnel configured within a VRF that is sourced from another VRF.
Workaround: There is no workaround.
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Symptoms: Standby reloads due to default ISIS metric maximum returns parser error.
Conditions: This issue is observed while configuring the ISIS metric maximum on an interface by using the isis metric maximum command and later changing it in to the default metric value.
Trigger: At this point, it will show the error, and the communication with the peer Supervisor has been lost then the standby reloads.
Workaround: There is no workaround.
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Cisco 10000, uBR10012 and uBR7200 series devices use a User Datagram Protocol (UDP) based Inter-Process Communication (IPC) channel that is externally reachable. An attacker could exploit this vulnerability to cause a denial of service (DoS) condition on affected devices. No other platforms are affected.
Cisco has released free software updates that address this vulnerability. Workarounds that mitigate this vulnerability are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080924-ipc.shtml.
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Symptoms: Devices running Cisco IOS may reload with the error message "System returned to ROM by abort at PC 0x0" when processing SSHv2 sessions. A switch crashes. We have a script running that will continuously ssh-v2 into the 3560 then close the session normally. If the vty line that is being used by SSHv2 sessions to the device is cleared while the SSH session is being processed, the next time an ssh into the device is done, the device will crash.
Conditions: This problem is platform independent, but it has been seen on Cisco Catalyst 3560, Cisco Catalyst 3750 and Cisco Catalyst 4948 series switches. The issue is specific to SSH version 2, and its seen only when the box is under brute force attack. This crash is not seen under normal conditions.
Workaround: There are mitigations to this vulnerability: For Cisco IOS, the SSH server can be disabled by applying the command crypto key zeroize rsa while in configuration mode. The SSH server is enabled automatically upon generating an RSA key pair. Zeroing the RSA keys is the only way to completely disable the SSH server.
Access to the SSH server on Cisco IOS may also be disabled via removing SSH as a valid transport protocol. This can be done by reapplying the transport input command with "ssh" removed from the list of permitted transports on VTY lines while in configuration mode. For example: line vty 0 4 transport input telnet end
If SSH server functionality is desired, access to the server can be restricted to specific source IP addresses or blocked entirely using Access Control Lists (ACLs) on the VTY lines as shown in the following URL:
http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/12.1_9_ea1/configur ation/guide/swacl.html#xtocid14
More information on configuring ACLs can be found on the Cisco public website: http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a00800a5b9a.shtml
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Symptoms: A router may crash spontaneously and display the following message:
%SYS-6-STACKLOW: Stack for process RIP Send running low, 0/6000Conditions: The symptom is observed on a router that is running Cisco IOS Release 12.2SB. RIP packets that go through many features in this environment (such as, RIP -> IP -> MLP -> PPP -> L2TP -> IP -> QoS/HQF -> driver) may also cause the stack overflow.
Workaround: There is no workaround.
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Symptoms: A few seconds after OSPF adjacencies come up, a router crashes because of a bus error.
Conditions: This symptom is observed on a Cisco router that functions as an ISR that is configured for OSPF.
Workaround: Add area 0 in the OSPF VRF processes.
Alternate Workaround: Enter the no capability transit command in the OSPF VRF processes.
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Symptoms: A Traffic Engineering (TE) tunnel does not re-optimize to explicit path after an MTU change.
Conditions: The TE tunnel is operating via explicit path. The MTU on outgoing interface is changed. OSPF is flapped, and it does not come up as there is MTU mismatch (MTU is not changed on peer router). Meanwhile the TE re- optimizes to a dynamic path-option as expected. Now the MTU is reverted back to the previous value, and the OSPF adjacency comes up. The TE tunnel does not re-optimize to explicit path. Manual re-optimization of the TE tunnel fails as well, and the TE tunnel sticks to the dynamic path.
Workaround: Enter the shutdown command followed by the no shutdown command on the particular interface.
•
Symptoms: When an IXIA-simulated BGP neighbor is not up, BGP is forced to delete the ARP entry for the IXIA host for a while. During that period, the router has to send ARP, and traffic is lost for a while.
Conditions: While observed with other protocols, this symptom was noticed with a typical BGP configuration in which the peers are nonexistent. This would cause the SYN to be retransmitted multiple times, and after some threshold, the ARP entry would be purged.
The ARP entries gets flushed out when the TCP retransmission timer expires. This causes the CEF adjacency to be lost, and performance can drop for packets going to that destination until the ARP is resolved again. This problem is not specific to BGP and is applicable to anything that rides over TCP.
Workaround: There is no workaround.
•
Symptoms: A BGP router may not send the default route to its neighbor.
Conditions: This symptom is observed when the neighbor default-originate command is conditionally configured with a route map and when the matching route is installed into the RIB by BGP itself.
Impacts: May impact traffic forwarding.
Workaround: There is no workaround.
•
Symptoms: The interface output rate (214 Mb/s) is greater than the interface line rate (155 Mb/s).
Conditions: This symptom is observed with a Cisco 7600/7500/7200-NPE400 and below. That is, PA-POS-2OC3/1OC3 (PULL mode).
Workaround: There is no workaround.
Further Problem Description: From the Ixia, packets are transmitted at 320 Mb/s. On the UUT (Cisco 7600), the outgoing interface (POS-Enhanced Flexwan) shows the output rate as 200 Mb/s. But the interface bandwidth is 155 Mb/s.
•
Symptoms: When the minimum number of links has joined a multilink bundle, Network Control Protocols (NCPs) such as IPCP fail to come up.
Conditions: This symptom can occur if both peers are configured with the ppp multilink links minimum mandatory command.
Workaround: Remove the ppp multilink links minimum mandatory command from the configuration.
•
Symptoms: A device with a PA-MC-2T3+ may reset because of a bus error if a channel group is removed while the show interface command is being used from another telnet session at the same time, and then the telnet session is cleared.
The device may also display Spurious Memory Accesses.
Conditions: These symptoms have been observed in the latest Cisco IOS 12.4T and 12.2S releases.
Workaround: Do not remove a channel group while using the show interface command for that interface.
•
Symptoms: A router crashes when a service policy is being attached, detached, or modified across a virtual template in the presence of traffic.
Conditions: This symptom is observed on a router that is configured with MLPPP over FR on channelized interfaces. The shaping is enabled at FR interface as well as in the service policy.
Workaround: There is no workaround.
•
Symptoms: MPLS forwarding table is empty on standby RP.
Conditions: This symptom is observed after ISSU loadversion, or simply when standby RP is reloaded.
Workaround: There is no workaround.
•
Symptoms: Router Crashed when removing grandchild policy
Conditions: Seen on a Cisco 7304 Router.
Workaround: There is no workaround.
•
Symptoms: A cbs3120 switch may crash during license installation, while reloading the slave switch that is being installed with license.
Conditions: This symptom is observed when:
1.
2.
Workaround: There is no workaround.
Further Problem Description: The issue is related to Inter-Process Communication (IPC). The crash is due to accessing an already freed port info. But the crash may be prevented by adding a check atcipc_notify_session_closure.
•
Symptoms: After an hw-module stop/start command sequence, the PPP over L2TPv3 sessions on that module may stop forwarding any traffic. The L2TPv3 control plane may be up and running but no data will be received over the L2 circuit.
Conditions: The symptoms occur on a Cisco 7300 series or 10000 series router when a hw-module slot name stop/start command is issued.
Workaround: Reboot the router.
•
Symptoms: A router may crash.
Conditions: The symptom is observed under the following steps:
1.
2.
3.
Workaround: There is no workaround.
•
Symptoms:
–
–
Conditions:
–
–
Workaround:
1.
2.
Further Problem Description: Both the above mentioned problems are happening because of the TCAM table entry.
•
Symptoms: A Cisco 7304 router may experience high CPU utilization (90-99%) when a large number (such as 2000) FR-L2TPv3 circuits are configured on a POS interface facing the CE router.
Conditions: A Cisco 7304 router that is configured with an NSE-100 and that is running Cisco IOS Release 12.2(33)SB.
Workaround: No other workaround than to reduce the scale of the circuits configured.
Further Problem Description: CPU utilization is proportional to number of FR- L2TPv3 circuits. So the issue occurs for any number of FR-L2TPv3 circuits, but rises gradually as the number of circuits increase.
•
Symptoms: It is observed that BGP updates can be delayed in MPLS VPN network by BGP Route-Reflector towards RR-clients resulting in slower convergence.
Conditions: This symptom is observed when BGP updates are delayed in MPLS VPN network.
Workaround: There is no workaround.
Further Information: This is an enhancement to the current route refresh mechanism and update groups.
•
Symptoms: Cisco 10000 Series Routers try to bring a configuration from a TFTP server (boot host). It appears the configuration gets transferred, but actually it is not accepted.
Conditions: This issue occurs when redundant PREs are configured and try to create a few hundred subinterfaces or ATM PVCs through a configuration file obtained from a TFTP server that is called by means of the boot host tftp command on the startup-config.
Workaround: Apply the copy tftp run command when either active or standby gets UP.
Further Problem Description: The following messages are seen in the console during the boot process:
Redundant RPs - Simultaneous configs not allowed:locked from consoleand then:
%SYS-5-CONFIG_I: Configured from tftp://(url of the config) by consoleBut it is not true. The file never actually gets to the active configuration.
Configuring RPR+ does not help. The same message is seen:
Simultaneous configs not allowed:locked from console•
Symptoms: Router may experience mwheel CPUHOG condition.
Conditions: This condition is observed on Cisco router while clearing all L2TP sessions when there are more than 2500 sessions with multicast traffic flowing on the sessions.
Workaround: There is no workaround.
•
Symptoms: A Cisco 7500 series router may crash.
Conditions: This symptom occurs when SSO is configured on the Cisco 7500 router and when we try to reconfigure an existing service policy.
Workaround: There is no workaround.
Further Problem Description: The router crashes when trying to reconfigure the service policy, which is already configured on the router. The crash is seen when we try to configure the random-detect dscp-based command.
•
Symptoms: Router reload is seen in the network with a traceback when the show aaa user all command is executed.
Conditions: This symptom occurs when the command is executed with 2k or more sessions in progress.
Workaround: Do not enter the show aaa user all command.
Further Problem Description: This is more like a timing or race condition, which could occur with a large number of sessions.
The show command outputs data from General DataBase which is typically a hash table for each session. However, it does not lock the table during the display for each session. When we have a large number of sessions, the output process may take more than one pass. Meantime if we clear the session, we free the memory associated with that session's General DB. Now, pointers the show command is using, point to a freed memory resulting in a reference to a bad pointer. The output process has to sleep (suspend) a moment, and the crash occurs.
•
Symptoms:
1.
router#show ip cef vrf <vrf name> x.x.x.x int
[snip]
MPLS short path extensions: MOI flags = 0x16 <-------MOI flags 0x10 is incorrectly set for iBGP when it becomes best path, correct flag should be 0x4, 0x5, 0x6 ...
correct now.2.
router#show ip cef vrf <vrf name> x.x.x.x int
[snip]
MPLS short path extensions: MOI flags = 0x5 <-------MOI flags 0x10 is
incorrectly clear for ibgp path when eBGP becomes best path, correct flag
should be 0x14, 0x15, 0x16...
correct now.Conditions: This symptom sometimes happens after BGP path update.
Workaround: Issue the clear ip route vrf vrf name x.x.x.x/y command.
•
Symptoms: MVPN PIM adjacency cannot be established over the MDT tunnel.
Conditions: The very basic functionality of MVPN is not functioning, because of which no multicast traffic can flow between PE2 and PE1.
Workaround: There is no workaround.
•
Symptoms: All incoming ISDN calls are rejected.
Conditions: This symptom occurs when a Cisco IOS router is:
–
–
This is seen in devices (Cisco 7206VXRs) that are configured for ISDN PRI dial- in with Dialer Profiles for backup purposes.
The problem could be reproduced in the lab where ISDN BRI i.o. PRI line is in use:
–
–
The Caller ID or DNIS binding cannot be used as all incoming ISDN calls have no Caller ID and the same DNIS.
Workaround: Upgrade to Cisco IOS Release 12.4(11)T or later releases, which also support NPE-G2.
•
Symptoms: A Cisco 10000 series router may reload unexpectedly during aggressive ISG PPPoA call bringup.
Conditions: The symptom is observed in system test on a Cisco 10000 series router that is running Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
•
Symptoms: In PRE2, the throughput of traffic sent in a given QOS class can flap.
Conditions: The symptom is seen when a class is overloaded with CIR=0.
Workaround: Use a policy-map with bandwidth instead of bandwidth remaining. This will set a CIR other than zero for those classes.
•
Symptoms: VPNv4 routes are not deleted from the VRF RIB when withdrawing VPNv4 BGP routes. This results in routes being present in VRF RIB, although the routes are not in the VPNv4 BGP table.
Conditions: This symptom happens when SSO is enabled.
Workaround: Remove SSO configuration from all BGP peers to avoid the problem. If the problem happens, use the clear ip route vrf vrf-name prefix command to clean up the related entry in RIB.
•
Symptoms: The router can crash due to bus error. The crash is seen after repeatedly after removing virtual-template interfaces under ATM.
Conditions: The crash is seen under the following conditions:
1.
2.
Repeating Step 2 continuously will cause a crash.
Workaround: There is no workaround.
•
Symptoms: High CPU load due to VTEMPLATE Backgr process.
Conditions: This symptom occurs when ip multicast boundary command is used on many interfaces (8000 or more).
Workaround: There is no workaround.
•
Symptoms: Dialer Cisco Express Forwarding (CEF) with IP accounting fails with packet counters returning zero for the member interface.
Conditions: This happens when ip accounting output-packets configured on NAS. The NAS is being checked for show adjacency detail which returns 0 packets and 0 bytes for the member interface.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series router may display the following message when altering MTU size on the ATM interface:
%C10KEVENTMGR-1-IRONBUS_FAULT: IB Stuck Pause Request Error 3/1, Restarting
Ironbus
%C10KEVENTMGR-1-IRONBUS_SUCCESS: IB Stuck Pause Request Error 3/1, Restart
SuccessfulConditions: This symptom may occur when changing MTU value on ATM interface and one of its subinterfaces. The error message is seen with the OC-3 ATM line card.
Workaround: There is no workaround.
•
Symptoms: SPAs in an MSC-100 may go missing.
Conditions: The symptom is observed when you have entered the hw- module slot slot_num stop command, then do a switchover and then enter the hw-module slot slot_num start command in a new active.
Workaround: Enter the command hw-module subslot slot_num reload.
•
Symptoms: Standby reloads due to RF timer expiry during SNMP platform sync.
Conditions: This symptom occurs when the system is coming up in stateful switchover (SSO) mode.
Workaround: There is no workaround.
•
Symptoms: SNMP counters on the 64-bit counters for incoming traffic, ifHCInOctets, are reporting very high values, different from what CLI reports, and even greater than the physical interfaces capacity.
Conditions: This symptom may be seen with all line cards (PA-CC, SPA, LCs) on a Cisco 7300 router with NSE-100 that is running c7300-p-mz.122-31.SB10.bin.
Workaround: There is no workaround.
•
Symptoms: Device crashes due to memory allocation issue.
Conditions: Observed on Cisco 7200, but this is not a platform-specific bug.
Workaround: There is no workaround.
•
Symptoms: On the CH-OC12 and CH-OC3 line cards, when issuing a controller no framing command while MR-APS is configured on the controller, the line card may reload.
Conditions: This symptom is observed on a Cisco 10000 series router.
Workaround: Remove MR-APS configs on controller before removing the framing (no framing).
•
Symptoms: When a large scale configuration of PPPoXoA sessions is used with ATM range PVCs using create-on-demand, it is possible to have a large quantity of tracebacks occur along with a 100% CPU utilization spike. During this event, sessions will not be able to connect or reconnect, and VTY connections will not respond. This occurs when some or all of the sessions are brought down.
Conditions: This symptom is seen with an environment of 8000 PPPoEoA sessions across 8000 create-on-demand range PVCs following the issuing of the clear pppoe all command.
Workaround: Do not bring down sessions in large quantities.
•
Symptoms: A multicast S,G entry is deleted and rebuilt every 3 minutes and 30 seconds. Additionally, the T bit is not set. Depending on the network topology and RP placement, this can break end to end multicast connectivity.
Conditions: This issue is seen on a Cisco 7304 NSE-100 with PXF enabled and is running Cisco IOS Release 12.2(31)SB5 or Release 12.2(31)SB11.
Workaround: Disable PXF or remove ip vrf select source from the source facing interface.
•
Symptoms: SP/LC might crash after SSO cutover.
Conditions: This problem is a timing issue and would be more easily seen in SSO cutover case.
Workaround: There is no workaround.
•
Symptoms: When a vendor client is l2-connected to an ISG interface, and the client does DHCP, the client will perform a DAD ARP after it receives the offer.
In the ARP, it uses 0.0.0.0 in the "sender-ip-address" field, in which the ISG will respond. This causes the client to assume this IP already exists on the network, and it sends back a DHCP decline to the DHCP server. Aside from the client failing to get an IP address, this issue can also deplete the IP pool.
Conditions: This symptom happens with some third-party vendor clients.
Workaround: If we get ARP REQ with source address 0.0.0.0, we would send IP_ARP_ACCEPT directly and let ARP handle this situation. Basically ISG does not want to influence in that case, so the relevant code changes.
•
Symptoms: A router may crash with the following error message:
%SYS-2-CHUNKBADFREEMAGIC: Bad free magic number in chunk header, chunk 6DF6E48
data 6DF7B48 chunk_freemagic EF430000 -Process= "Check heaps", ipl= 0, pid= 5,
-Traceback= 0x140C170 0x1E878 0x1EA24 0x1B4AC 0x717DB8
chunk_diagnose, code = 2
chunk name is PPTP: pptp_swi
current chunk header = 0x06DF7B38
data check, ptr = 0x06DF7B48
next chunk header = 0x06DF7B70
data check, ptr = 0x06DF7B80
previous chunk header = 0x06DF7B00
data check, ptr = 0x06DF7B10Conditions: This issue has been seen on Cisco 7200 router with NPE-G2 configured for L2TP and running Cisco IOS Release 12.4(15)T3 and Cisco IOS Release 12.4(15)T4.
Workaround: There is no workaround.
•
Symptoms: Local switching connection will not pass traffic after using the hw-module reset command.
Conditions: This symptom occurs while doing hw-module reset slot, where local switching connection is configured with at least one segment as ATM PVC on slot.
Workaround: Micro code reload will bring the system back.
•
Symptoms: A Cisco 10000 series router may crash when configured for Authentication, Authorization, and Accounting (AAA).
Conditions: No special conditions are known for causing this crash.
Workaround: There is no workaround.
Further Problem Description: The issue was reported for a customer specific special based on Cisco IOS Release 12.2(31)SB9.
•
Symptoms: A Cisco 10000 router sends out ARP and PPPoE active discovery control packets with CoS bits as 6 in 802.1Q header (these bits are also referred as Priority Bits) Cisco IOS Release 12.2(31)SB. This has been a behavior difference from earlier releases, which can bring out issues in network if such packets are treated differently.
For example, a network which is configured to drop packets with CoS value 6 would see behavior difference.
Conditions: This is a default condition.
Workaround: Configure network to allow packets with different CoS values. Note that this is applicable only if the network is configured to drop such packets.
•
Symptoms: ToS is always 0x00 when exporting the Netflow information to the Netflow collector. In the output of the sh ip cache verbose flow command, the ToS value is correct.
Conditions: This symptom is observed on a router that is running with PXF and using Netflow Export version 5.
Workaround: Disable PXF with the no ip pxf command.
•
Symptoms: Router crashes due to bus error. The crash is seen after repeatedly removing virtual-template interfaces under ATM.
Conditions: The crash is seen under the following conditions.
1.
2.
Repeating Step 2 continuously will cause a crash.
Workaround: There is no workaround.
•
Symptoms: Some ATM subinterfaces stop the output of the packets after SSO. After shut/no shut on the defective subinterface, it comes to output the packets.
Conditions: Though the Encap String is displayed on the normal subinterfaces by the show ip cef VRF IP plat command, no Encap String is displayed on the defective subinterface after the SSO by the show command.
Encap String:
After shut/no shut on the defective subinterface, Encap String comes to be displayed on it by the show command.
Encap String: 0408000000000000AAAA030000000800Workaround: There is no workaround.
•
Symptoms: Whenever a subinterface is created on ESR-6OC3/P-SMI with Cisco IOS c10k2-k91p11-mz.122-31.SB9a, it sends an error. It works fine with Cisco IOS Release 12.2(27)SBB4c.
Conditions: Unknown.
Workaround: There is no workaround.
•
Symptoms: When a downgrade is done from Cisco IOS Release 12.2(33)SB to Release 12.2(31)SB, the Standby that is loaded with Cisco IOS Release 12.2(31)SB fails to do config sync and keeps crashing.
Conditions: This symptom occurs when both Active and Standby are loaded with Cisco IOS Release 12.2(33)SB image with PPPOX (PPPoA or PPPoE) configurations. Standby is downgraded to Cisco IOS Release 12.2(31)SB. The standby loaded with Cisco IOS Release 12.2(31)SB fails to do configuration sync and keeps crashing after configuring issu loadversion command.
This is also seen in the case of an upgrade from Cisco IOS Release 12.2(31)SB* to Cisco IOS Release 12.2(33)SB image, after issu runversion command, when Active has Cisco IOS Release 12.2(33)SB and Standby has Cisco IOS Release 12.2(31)SB* image.
Workaround: For upgrade from Cisco IOS Release 12.2(31)SB* to Cisco IOS Release 12.2(33)SB image:
After issu runversion command, when Active has Cisco IOS Release 12.2(33)SB:
1.
router#configure terminal
router(config)#redundancy
router(config-red)#force-rpr 12.
3.
For downgrade from Cisco IOS Release 12.2(33)SB to Cisco IOS Release 12.2(31) SB* image:
1.
router#configure terminal
router(config)#redundancy
router(config-red)#force-rpr 12.
3.
4.
The force-rpr 1 command is removed from the configuration by now, since Cisco IOS Release 12.2(31)SB* image does not support this command.
•
Symptoms: A Cisco PRE-2 that is running Cisco IOS Release c10k2-k91p11-mz.122- 27.SBB4c image crashes and fails after customer removes an interface and ran some show commands.
Conditions: This symptom is observed on a Cisco 10000 series PRE-2.
Workaround: There is no workaround.
•
Symptoms: Sessions come up on LNS even after the associated VT on the LAC has been removed.
Conditions: This symptom is seen when the BBA group should have virtual- template configured in it even after deleting the virtual-template interface.
Workaround: Remove virtual-template configuration from the BBA group.
•
Symptoms: There may be a small amount of memory leak for each PPP connection.
Conditions: The symptom is observed when PPP authorization is in use and the PTA session flaps. This problem will be seen only when the ip address pool or ip address commands are assigned from the radius-server.
Workaround: There is no workaround.
Further Problem Description: PPP attempted to set authorization information into IPAM for each connection. But the attempt by IPAM to store that information in the PPP Author sub-block off the PPP context failed because of the failed registration. The error exit for this failure did not clean up the IPA block just created and caused the memory to leak. This leak occurred on every PPP connection.
•
Symptoms: When an interface is shut, the LC reloads and PRE switches over. On the new active when the interface is no shut, the VCs do not come up.
Conditions: This symptom is observed on the Cisco 10000 series router.
Workaround: If PVC is in DOWN state, do a shut followed by a no shut to recover. If PVC is in INACT state, resetting the LC is required to recover.
•
Symptoms: For iEdge policies on the Cisco 10000 series router, if the TCAM entries get full, there will be a perpetual high CPU of greater then 90%, with SuperACL accounting for most of the CPU use.
Conditions: The risk of hitting this condition increases for specific combinations of iEdge traffic classes, where there are many overlapping ACE entries across the traffic classes.
Workaround: Avoid having overlapping ACEs across traffic classes that are part of the iEdge policy.
•
Symptoms: System crash or memory corruption occurs.
Conditions: Occurs when repeated line card resets are seen in the device or repeated line card online insertion and removal (OIR) operations are performed.
Workaround: There is no workaround.
•
Symptoms: Standby reloads following cutover.
Conditions: This symptom occurs during an upgrade to Cisco IOS Release 12.2(33) SB on Cisco 10000 series router with RPR+ configured redundancy mode. This results in RPR fallback mode being employed (correctly) and with PRE-B as the active, running the earlier release.
Workaround: Perform the upgrade procedure with PRE-A as the active and PRE-B as standby.
•
Symptoms: The following message is printed on the console:
Policy-map installation via subscriber-profile not supportedConditions: This symptom occurs when an unsupported policy-map is downloaded via the subscriber profile.
Workaround: There is no workaround other than not using unsupported policy maps.
Further Problem Description: If this happens to 32,000 sessions, then 32,000 messages will be printed on the console at 9,600 baud.
•
Symptoms: A router may crash from memory corruption.
Conditions: The symptom is observed when a QOS policy is added to the service template in the BroadHop. It may also be observed if service with TC and L4Redirect action is installed on a subscriber profile.
Workaround: There is no workaround.
•
Symptoms: An E1 controller may flap due to RMAI alarms, even after an internal loop in ESR (with internal clocking) is added.
Conditions: The symptom is observed on an ESR that is running Cisco IOS Release 12.2(31)SB.
Workaround: Use the temux force workaround ds1e1 x y command.
Further Problem Description: This issue appears to be corner case.
•
Symptoms: A router that is running in SSO mode can crash when PPPoX sessions are being brought up with the following messages appearing in crashinfo file and on router console:
%SYS-3-OVERRUN: Block overrun at 7A3280D8 (red zone 00000000)
%SYS-6-BLKINFO: Corrupted redzone blk 7A3280D8, words 2348, alloc 605CAEC8,
InUse, dealloc 0, rfcnt 1Conditions: This symptom occurs when a router that is running in SSO mode may crash when PPPoX sessions are being brought up. The crash does not occur when local authentication method is used.
Workaround: There is no workaround.
•
Symptoms: DBS enabled VCs are not syncing to standby RP. This issue is reproducible even with a single VC when the router is reloaded.
Conditions: This symptom is observed on a Cisco 10000 series router that is a HA setup with SSO mode configured.
Workaround: Resetting the standby will bring the VCs up.
Further Problem Description: This will effect the synchronization of PPP sessions to standby.
•
Symptoms: With eiBGP multipath, incoming labeled packets may get looped in MPLS core instead of getting forwarded to CE, causing traffic issues. The following symptom may be found:
–
Dec 17 07:44:46.734 UTC: %COMMON_FIB-3-BROKER_ENCODE: IPv4 broker failed to
encode msg
type 0 for slot(s) 0B
-Traceback= 6044E470 60465864 6043BCFC 6043B570–
Mar 31 17:44:40.576 UTC: FIBrp_xdr: Table IPv4:<vrf name>, building insert
event xdr for x.x.x.x/y. Sources: RIB
Mar 31 17:44:40.576 UTC: FIBrp_xdr: Encoding path extensions ...
Mar 31 17:44:40.576 UTC: FIBrp_xdr: - short ext, type 1, index 0
Mar 31 17:44:40.580 UTC: FIBrp_xdr: Getting encode size for IPv4 table broker
FIB_FIB xdr
Mar 31 17:44:40.580 UTC: - short path ext: len 12
Mar 31 17:44:40.580 UTC: - short path ext: len 24
Mar 31 17:44:40.580 UTC: - feat IPRM, len 12
Mar 31 17:44:40.580 UTC: => pfx/path 113 + path_ext 24 + gsb 8 + fs 16 = 161–
router#<CmdBold>show mpls forward vrf <vrf name> x.x.x.x<noCmdBold>
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or VC or Tunnel Id Switched interface
937 No Label x.x.x.x/y[V] \
0 drop <========= it is drop–
router#<CmdBold>show ip cef vrf <vrf name> x.x.x.x int<noCmdBold>
[snip]
path_list contains at least one resolved destination(s). HW not notified
path 70BFFC5C, path list 20E87B58, share 1/1, type recursive nexthop, for
IPv4, flags resolved
MPLS short path extensions: MOI flags = 0x16 <-------MOI flags 0x10 is
incorrectly set (for ebgp path, correct flag should be 0x4, 0x5, 0x6 ..)
correct now.
[snip]Conditions: The eiBGP multipath is enabled; iBGP path comes up first, then the eBGP path. Both eBGP and iBGP paths could be in MPLS forwarding causing the issue.
Workaround: Using the clear ip route vrf name x.x.x.x clears the issue.
•
Symptoms: A crash may occur when a PPPoX session with an active Lawful Intercept (LI) tap is disconnected.
Conditions: This symptom is observed when SNMP LI tap is applied to a PPPoX session. Session disconnect is required.
Workaround: There is no workaround.
•
Symptoms: For a DS3E3 ATM line card, if the line card is reset with any one of the 8 ports shut, the card comes up fine and all the VCs in the UP port work fine.
On no shut of the previously shut port:
–
–
Conditions: This symptom is observed only in DS3 ATM line card.
Workaround: Reset the card again to recover the failed VCs.
•
Symptoms: A Cisco 10000 series router with POS card with redundant PREs is running Cisco IOS Release 12.2(31)SB2 in RPR+ mode. The POS interface is using PPP encapsulation. When the Cisco IOS is upgraded from Cisco IOS Release 12.2(31)SB2 to Release 12.2(31)SB10, the POS interface does not come up after redundancy failover.
Router>en
Router#sh ip int brie
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0/0 unassigned YES NVRAM up down
POS5/0/0 10.10.10.2 YES NVRAM down downConditions: This symptom is seen when the Cisco IOS is upgraded to Cisco IOS Release 12.2(31)SB210 and Release 12.2(31)SB11 using the following procedure:
1.
2.
3.
4.
5.
Workaround: A shut/no shut on the POS interface will bring up the POS interface with PPP encapsulation.
Router#sh ip int brie
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0/0 unassigned YES NVRAM up down
POS5/0/0 10.10.10.2 YES NVRAM down down
Router#
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#int pos5/0/0
Router(config-if)#shut
Router(config-if)#
00:06:36: %C10K_ALARM-6-INFO: CLEAR CRITICAL POS 5/0/0 Physical Port Link Down
00:06:36: %C10K_ALARM-6-INFO: ASSERT INFO POS 5/0/0 Physical Port Administrative State Down
00:06:36: %LINK-5-CHANGED: Interface POS5/0/0, changed state to administratively down
Router(config-if)#no shut
Router(config-if)#
00:06:44: %C10K_ALARM-6-INFO: CLEAR INFO POS 5/0/0 Physical Port Administrative State Down
00:06:44: %LINK-3-UPDOWN: Interface POS5/0/0, changed state to up
00:06:44: %C10K_ALARM-6-INFO: ASSERT CRITICAL POS 5/0/0 Line Remote Failure Indication
00:06:44: %SONET-4-ALARM: POS5/0/0: LRDI
00:06:59: %C10K_ALARM-6-INFO: CLEAR CRITICAL POS 5/0/0 Line Remote Failure Indication
00:07:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface POS5/0/0, changed state to up
Router(config-if)#^Z
Router#
Router#sh ip int brie
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0/0 unassigned YES NVRAM up down
POS5/0/0 10.10.10.2 YES NVRAM up up
Router#•
Symptoms: A router crashes while removing the policy in the c10k_iedgre_extract_tc function.
Conditions: There should be around 24k sessions with extremely low memory at the box, and sessions should be flapping (coming and going). There should also be traffic class applied to the session.
Workaround: There is no workaround.
•
Symptoms: Memory is used and held by the EXEC process or found in *Dead*.
Conditions: The symptom is observed when the show sss session detailed command is used, and the ISG policy map is configured with "subscriber condition-map match-any internet-service."
Workaround: There is no workaround.
•
Symptoms: Stats for a few ACL templates are not updated correctly.
Conditions: This symptom occurs when there is a large number of ACLs (4096). Send traffic across and check the stats on all of them.
Workaround: There is no workaround.
•
Symptoms: For certain iEdge traffic class configurations, the SuperACL process may consume hundreds of megabytes of memory. While it releases this memory, the sudden spike in memory consumption (for example, when an iEdge policy is compiled due to a new incoming session) has the potential to create other system failures.
Conditions: The symptoms can be triggered if there are four or more traffic classes in an iEdge policy, and there are several duplicate ACEs across these traffic classes. The issue is amplified with the number of iEdge traffic classes.
Workaround: Optimize the traffic class configurations. For example, remove the duplicate ACEs that may be present across several traffic classes.
•
Symptoms: The LSP ping is not working over GRE tunnel.
Conditions: This symptom occurs with PXF enabled.
Workaround: There is no workaround.
•
Symptoms: The bandwidth of the police percent is not updating properly for Multilink PPP over ATM (MLPoATM), LFI over ATM (LFIoATM), LFI over Frame Relay (LFIoFR) and single member MLP on LNS, when attaching the policy map to the Multilink interface.
Conditions: The symptoms are observed when bringing up the MLPoATM, LFIoATM, LFIoFR and single member MLP on LNS with a single link and attaching the police percent on the Multilink interface.
Workaround: Use police absolute value instead of police percent.
•
Symptoms: The following error messages may start showing up in syslog:
%IDBINDEX_SYNC-3-IDBINDEX_ENTRY_ADD: Cannot add entry to interface index
table: "", 21
%COMMON_FIB-2-IF_NUMBER_ILLEGAL: Attempt to create CEF interface for Virtual-
Access2.2631 with illegal if_number: -1Conditions: This occurs after the box has gone through some sessions churning and switchovers.
Workaround: There is no workaround.
Further Problem Description: If these messages appear in syslog continuously, schedule a reboot before it crashes.
•
Symptoms: Flow accounting records (start/stop/interim) may not be generated for PPP sessions.
Conditions: The symptom is observed when Traffic-Class based service is applied to a PPP session using on-box configuration or service log-on.
Workaround: There is no workaround.
•
Symptoms: Port adapter carrier card loss of heartbeat occurs as seen in the following display:
%PACC-3-HEARTBEAT_LOSS: PA Carrier Card Loss of heartbeatConditions: This symptom happens when a router boots up with all the PAs up.
Workaround: There is no workaround.
•
Symptoms: If the service-policy is attached on the main interface and packets are routed through the sub interface, the packets are not egressed out. Also PACC-3-HEART_LOSS is seen on the port-adapters.
Conditions: This issue is seen with Cisco 7300(NSE-100) router with PXF enabled.
Workaround: Disable PXF using the no ip pxf command.
•
Symptoms: Convergence time is greater than expected in high availability SSO mode.
Conditions: This issue occurs only when the no aaa new- model command is enabled for high available sessions such as PPPoSerial that do not need external AAA server support. This issue is observed with more than 2000 serial interfaces.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series router crashes on loading negative configurations.
Conditions: This symptom happens when loading provisioning/unprovisioning LS and/or PW connection scale configurations from TFTP while executing the show xconnect all detail command on other console.
Workaround: There is no workaround.
•
Symptoms: VRF may not get deleted if the VRF NAME size is 32 characters on a dual RP HA/SSO router.
Conditions: This symptom occurs when adding a VRF with 32 characters on a DUAL RP HA router. (In some releases a VRF name with more than 32 characters will get truncated to 32.) The following may occur:
–
–
Workaround: There is no workaround.
•
Symptoms: On a Cisco 10000 series router, after some hours of normal operation, both input and output traffic accounting stops increasing for volume monitor prepaid services associated with a random ISG session.
Conditions: The symptom is observed with ISG sessions with volume monitor prepaid service only and this is been seen when the drop is set while doing a reauthorization. The issue is seen only when the policy is been shared by multiple ISG sessions.
Workaround: Configure an explicit event to set a drop to FALSE in the control policy at quota depletion/exhaustion.
•
Symptoms: A router may crash while trying to execute the show interface serial command on a 4CHSTM1 card.
Conditions: The symptom is observed when a channel is removed and the corresponding show interface serial command is executed simultaneously from the other VTY.
Workaround: Execute the show interface serial command only after the channel is removed.
•
Symptoms: Standby continuously reboots after switchover.
Conditions: This symptom occurs on an optimally loaded router (router with some 300k routes) when switchover is performed after change in configuration without performing a reload.
Workaround: Perform reload on the router before performing switchover whenever there is any major configuration changes on the router.
•
Symptoms: Topology:
Router PPPoE/PPPoA <----> 7301.
The PPP session is established with the Cisco 7301, which is ISG enabled.
When traffic reaches 1 gigabyte, the accounting attribute will be corrupted with 2^32 - 1.
The expectation of the gigabyte word is when it reaches 4294967295 bytes, it will increment with 1 gigaword.
The problem is seen in the following releases:
Cisco IOS Release 12.2(31)SB11: per-user service account corrupts the gigaword, and per-user session is correct.
Cisco IOS Release 12.2(31)SB12: per-user service account corrupts the gigaword, and per-user session does not show anything at all.
Cisco IOS Release 12.2(33.1.10)SB1: per-user service account shows nothing in the gigaword, and per-user session is correct.
Conditions: When traffic reaches 1 gigabyte, the accounting attribute will be corrupted with 2^32 - 1.
Workaround: There is no workaround.
•
Symptoms: The standby may reload when upgrading the software from Cisco IOS Release 12.2(31)SB to Cisco IOS Release 12.2(33)SB1.
Conditions: This symptom occurs at run version during client verification.
Workaround: There is no workaround.
•
Symptoms: The standby PRE may reset after adding an ISG service policy to a Virtual-Template, followed by the clear pppoe all command. New sessions start coming up.
Conditions: This problem may occur after adding an ISG service policy to a Virtual-Template, followed by the clear pppoe all command. New sessions start coming up.
Workaround: There is no workaround.
•
Symptoms: A router crashes after a couple of switchovers in the Cisco 10000 iEdge area.
Conditions: This symptom is observed when ISG policies are configured at the router. A couple of switchovers must be done.
Workaround: There is no workaround.
Further Problem Description: This problem occurs due to the virtual access numbers (if_number) equal to -1.
•
Symptoms: A router crashes due to a TLB exception.
Conditions: This symptom is seen while deleting the class-default class map in a MQC policy map that is applied to thousands of PPPoX sessions.
Workaround: There is no workaround.
•
Symptoms: Features intermittently fail to be installed for users.
Conditions: This symptom occurs under the following conditions:
–
–
–
Workaround: Reload, or if possible switchover to other PRE.
•
Symptoms: A router crashes when unconfiguring multipoint ATM subinterface that is configured to bring up PPPoA sessions.
Conditions: This symptom is seen when unconfiguring multipoint ATM subinterface that is configured to bring up PPPoA.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series router (PRE3) crashes on active and standby PRE3 with the following error:
PRE3 crash: COB3_FCPU_LQ_OFF_ERR: Low Priority Offset ErrorConditions: This symptom is observed on a Cisco 10000 series router that is running Cisco IOS Release 12.2(31)SB10.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB12
Cisco IOS Release 12.2(31)SB12 is a rebuild release for Cisco IOS Release 12.2(31)SB. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB12 but may be open in previous Cisco IOS releases.
Miscellaneous
•
Symptoms: A memory leak may occur in the "IP Input" process on a Cisco platform, and memory allocation failures (MALLOCFAIL) may be reported in the processor pool.
Conditions: This symptom is observed on a Cisco platform that is configured for Network Address Translation (NAT).
Workaround: There is no workaround.
•
Symptoms: The interface-type and interface-number arguments in the distribute-list address family configuration command do not function.
Conditions: This symptom is observed on a Cisco platform that integrates the fix for caveat CSCea59206. A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCea59206. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround.
Further Problem Description: The fix for CSCed84633 re-enables the interface-type and interface-number arguments in the distribute-list address family configuration command for both VRF interfaces and non-VRF interfaces.
•
Symptoms: A CPUHOG may occur.
Conditions: This symptom is observed with various routing commands, including the clear ip route command, in cases where more than 300,000 routes were learned via a single subnet.
Workaround: There is no workaround.
•
Symptoms: A spurious memory access may be generated on a router.
Conditions: This symptom is observed on a Cisco router when you configure an ATM VC on which PPPoE sessions are established. The trigger is when the VC is torn down.
Workaround: There is no workaround.
•
Symptoms: When the virtual-profile command is configured, PPP sessions do not come up.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
•
Symptoms: PPP may not start on a serial interface that is physically up. When this situation occurs, inspection of the interface via the show interface command shows that the physical layer is up, but that the line protocol is down, and that LCP is closed.
Conditions: This symptom is observed only on regular serial interfaces that use PPP encapsulation. The symptom does not occur with tunneling mechanisms such as PPP over ATM (PPPoATM) or VPDN sessions. The symptom may occur when the physical layer undergoes multiple state transitions, starting from an up state and ending in an up state, with the entire sequence occurring over a short period of time. In such a situation, event filtering mechanisms in Cisco IOS software may prevent a notification from being sent to PPP when the link returns to an up state, and, in turn, PPP from (re-)starting on the interface. The most likely time for such a situation to occur is when PPP itself resets the interface, which occurs when an existing PPP session is terminated because of a keepalive failure or LCP negotiation failure.
Workaround: Any sequence that resets the physical layer and that is slow enough that the filtering mechanisms do not once again intrude is sufficient to restart PPP. For example, you can restart PPP on the interface by entering the shutdown interface configuration command followed by the no shutdown interface configuration command.
•
Symptoms: A short CPU hog seen in the ATM PA Helper process when an interface flaps and the framing configuration is modified on the interface.
Conditions: This symptom is observed on a Cisco 7200 with a PA-A3-T3 adapter that is running Cisco IOS Release 12.2(25)S or 12.2(31)SB (and possibly other Cisco IOS releases).
Workaround: There is no workaround.
Further Problem Description: The CPU hog is enough to cause OSPF adjacencies (with fast hello) to go down on other unrelated interfaces. The same problem is seen if BFD is configured.
•
Symptoms: An ISG configured for RADIUS proxy may see a dummy RADIUS proxy context being created when an accounting stop packet is received.
Conditions: This symptom is observed when accounting forwarding is configured and an accounting stop comes when no subscriber session exists for that user.
Workaround: There is no workaround. However, this is a negative case where the ISG receives a stop record before a start record.
•
Symptoms: A router that functions under a heavy load with SSHv2 clients may crash if any of the SSH clients are terminated.
Conditions: This symptom is observed on a Cisco 7600 series when the following conditions are present:
–
–
–
–
–
Workaround: Do not use SSHv2 when the router is very stressed.
•
Symptoms: BGP convergence is very slow, and CPU utilization at the BGP Router process is always near 100 percent during the convergence at the aggregation router. This issue obviously shows the following tendencies:
1) The greater the number of component prefixes that belong to the aggregate- address entry, significantly slower convergence is seen at the aggregation router.
2) The greater the number of duplicate aggregation component prefixes for the aggregate-address entry, seriously slower convergence is seen at the aggregation router.
Conditions: Any release would be affected if "aggregate-address" is configured and routing updates are received every few seconds.
Workaround: Remove the "aggregate-address."
Further Problem Description: If you configure "aggregate-address" lines after BGP convergence has been achieved, the BGP process only holds about 60 or 80 percent of the CPU for about 1 minute. However, if you do peer reset after "aggregate-address" entries have been configured, the convergence time is about 32 minutes (it is about 6 minutes if "aggregate-address" entries are removed).
•
Symptoms: Removal of VRF via "no ip vrf..." in global configuration mode or "no ip vrf forwarding..." in interface configuration mode.
Conditions: VRF and IP Multicast may be required for the symptom to occur.
Workaround: Make changes to the startup configuration of the router, and reload the router during a service window.
•
Symptoms: Tracebacks may be generated for all accounting messages.
Conditions: This symptom is observed on a Cisco router that is configured for AAA.
Workaround: There is no workaround.
•
Symptoms: A router reloads unexpectedly because of malformed DNS response packets.
Conditions: This symptom is observed when you configure name-server and domain lookup.
Workaround: Configure the no ip domain lookup command to stop the router from using DNS to resolve hostnames.
•
Symptoms: A router crashes during an online insertion and removal (OIR) of a multilink interface.
Conditions: This symptom is observed on a Cisco 7200 series that is configured for MLP and PPP.
Workaround: Shut down the multilink interface before you perform an OIR.
•
Symptoms: The show sss session detailed command displays traffic for the default traffic class (TC) as "Unmatched Packets (dropped)."
Conditions: This symptom is observed irrespective of the configuration; for example, whether the default TC is set to forward or drop the traffic.
Workaround: There is no workaround.
•
Symptoms: The Route Processor (RP) crashes.
Conditions: Some of the Protocol Independent Multicast (PIM) CLI commands are causing the active RP to crash. The crash happens only when these commands are configured while in control-plane policing subconfiguration mode. Normally, any global relevant configuration should automatically exit the subconfiguration prompt and also accept the command. In this case, the PIM command is rejected and the RP crashes. The same PIM commands work fine when entered under global configuration mode (where they belong) or under other subconfiguration modes.
Workaround: Use the exit command to exit the main configuration prompt before configuring PIM-related commands.
•
Symptoms: A PIM hello message may not reach the neighbor.
Conditions: This symptom is observed on a Cisco router when an interface comes up and a PIM hello message is triggered.
Workaround: Decrease the hello timer for PIM hello messages.
Further Problem Description: The symptom occurs because the PIM hello message is sent before the port can actually forward IP packets. IGP manages to get its neighborship up but PIM does not, causing RPF to change to the new neighbor and causing blackholing to occur for up to 30 seconds.
•
Symptoms: FastStart does not function on PPP interfaces. (FastStart is enabled by default for regular serial interfaces.)
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2 SB.
Workaround: There is no workaround.
Further Problem Description: FastStart acts as a partial solution for the condition that is described in caveat CSCek77555, because FastStart enables an inbound packet from a peer to trigger the startup of PPP (that is, FastStart brings PPP out of the inert state that is documented in caveat CSCek77555).
•
Symptoms: A router may crash when applying Dynamic Bandwidth Selection (DBS) parameters to a PPPoE session.
Conditions: This issue arises only when the dbs enable command is configured on an ATM PVC and QoS parameters are applied from RADIUS. This can be reproduced only with one PPPoE PTA session. If the dbs enable command is not configured, the crash is not seen.
Workaround: Disable DBS.
Further Problem Description: Operational impact.
•
Symptoms: A PRE3 crashes if attempts are made to re-establish ISG sessions when CEF IDB is depleted. The show cef idb command indicates that CEF IDB is not released when subscriber sessions are all torn down after an HA switchover.
Tracebacks and error messages of COMMON_FIB-2-IF_NUMBER_ILLEGAL flush on the console during sessions establishment.
Conditions: This symptom is observed when attempts are made to re-establish ISG sessions when CEF IDB is depleted.
Workaround: There is no workaround.
•
Symptoms: A router may crash because of a bus error.
Conditions: The router must be configured for L2TP.
Workaround: There is no workaround.
•
Symptoms: The control policy rule cannot match a specific class map for the event of credit-exhausted. Debugs show no match for the rule. Only if you use "always" in the class type control for the event credit-exhausted can the rule be applied.
Conditions: This symptom is observed when a credit exhaust event is configured for a prepaid service.
Workaround: There is no workaround.
•
Symptoms: When attribute 31 and TC (per service) are configured, NO CSID is sent on accounting record for IP sessions.
Conditions: This symptom is observed with an IP session with TC services and attribute 31 configured.
Workaround: There is no workaround.
•
Cisco IOS emits the %DATACORRUPTION-1-DATAINCONSISTENCY error message whenever it detects an inconsistency in its internal data structures.
A traceback appears after the error message. This traceback is encountered with long URLs.
It is important to note that this error message does not imply that packet data is corrupted. However, it does provide an early indicator of other conditions that can eventually lead to poor system performance or a Cisco IOS restart.
•
Symptoms: The state of the AAA server always shows UP, even when the interface connected to the server was shut down (cnx port is shut (admin down)).
Conditions: This symptom is observed when the following CLI is configured on the NAS:
radius-server host ip-address auth-port 2295 acct-port 2296 test username username idle-time 1 key cisco
With this CLI configured, the NAS requests are sent to the server, and then disconnecting the interface connected to the AAA server from the NAS, and when issuing the show aaa servers command, the state of the AAA server is shown as UP/DOWN.
Impact: Display issue.
Workaround: There is no workaround.
•
Symptoms: OAM cells are not generated when a new ATM subinterface and PVC are configured. Subinterface status is up/up; PVC is down. No debug output is seen with the debug atm oam interface atmx/x.xxx command.
Conditions: This symptom is observed when a new ATM subinterface and PVC are configured.
Workaround: Execute the shut/no shut commands on the ATM subinterface.
•
Cisco IOS Software Multiprotocol Label Switching (MPLS) Forwarding Infrastructure (MFI) is vulnerable to a Denial of Service (DoS) attack from specially crafted packets. Only the MFI is affected by this vulnerability. Older Label Forwarding Information Base (LFIB) implementation, which is replaced by MFI, is not affected.
Cisco has released free software updates that address this vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080924-mfi.shtml.
•
Symptoms: Service level accounting will not install on a TC session, and no error message will be generated. No failure will be generated, and the TC session will remain established.
Conditions: This symptom is observed on any TC session with service accounting. This applies to both IP and PPPox parent sessions.
Workaround: There is no workaround.
•
Symptoms: With no traffic on a PA-A6-OC3SMi card, the max ICMP pings times are seen at 352 to 384 ms when testing to an ATM loopback diag. Min/avg are 1/4. This is seen with 1500-byte packets.
Conditions: This symptom is observed with a 7206vxr backplane version 2.8- 2.11 with the PA-A6-OC3SMi ATM card.
Workaround: There is no workaround.
Further Problem Description: This symptom is not observed with version 2.8- 2.11 with the PA-A3-T3 card.
Sending 200, 1500-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Success rate is 100 percent (200/200), round-trip min/avg/max = 1/3/352 ms Router# ping 10.1.1.1 repeat 200 size 1500•
Symptoms: A Cisco router that is configured with MPLS might have problems forwarding MPLS packets if fragmentation of these packets is required.
Conditions: This symptom is observed on a Cisco 7200 with NPE-G1 that is running Cisco IOS Release 12.2(31)SB6 and SB7 but could be present in other platforms and releases.
If the router needs to send large MPLS packets, the issue might appear when the router needs to fragment them (due to MTU constraints).
Impact: Traffic broken for large packets.
Workaround: There is no workaround.
•
Symptoms: PVC stays INACTIVE when doing PRE switchover with ATM APS.
Conditions: The primary ATM card of the APS pair is shutdown and then no shutdown. And a PRE switchover is done. Now the ACTIVE APS circuit shows the ATM PVCs as DOWN. Sending traffic over these ATM PVCs can generate the message "%C10K-2-BADRSRCNUM: Invalid resource number from PXF."
Workaround: There is no workaround.
•
Symptoms: The show ip subscriber dangle command may cause a crash.
Conditions: This symptom is observed in Cisco IOS Release 12.2(31)SB01 and later releases when there are dangling IP sessions.
Workaround: There is no workaround.
•
Symptoms: A system crash may occur during the start of a PPPoA ISG session because of a bus error.
Conditions: During the start of a PPPoA session with an ISG configuration, Cisco IOS software may experience a bus error and a subsequent crash while processing the access-accept from the RADIUS server. The access-accept will include ISG services to be started on the session indicated by VSA 250 RADIUS attribute-value pairs.
Workaround: This is a very rare instance, and there is no workaround.
•
Symptoms: More than 32,768 TC sessions cannot be brought up, and an "Out of IDs" AAA traceback message is displayed.
Conditions: This symptom is observed under TC sessions.
Impact: Traceback preventing scale of ISG PPP Traffic Class. Scalability issue.
Trigger: While running ISG sessions with PPPoL2TP LAC/LNS on a Cisco 10000, unable to bring up more than 32,768 TC sessions because of the following "Out of IDs" AAA traceback message:
Nov 13 11:00:56.696 EST: %IDMGR-3-INVALID_ID: bad id in id_get (Out of IDs!)AAA is allocating only 1024*32 = 32,768 IDs. Not able to bring up any more sessions because of accounting flow ID allocation failure.
Workaround: There is no workaround. Traffic classes cannot scale beyond 32,768.
•
Symptoms: Duplicate multicast packets are observed on some interfaces in the multicast output list. Packets are replicated twice on some interfaces.
Conditions: If the interface that has an incoming multicast stream also appears in the output list of the mroute, there could be duplicate packets on some interfaces forming the output list.
Workaround: There is no workaround.
•
Symptoms: CPUHOGs are seen for 16,000 PPPoEQinQ sessions while traffic is being passed.
Conditions: This symptom is observed when there are 16,000 sessions over 16,000 PPPoEQinQ subinterfaces and when those sessions have L4R configured over them.
Workaround: There is no workaround.
•
Symptoms: Redistribution from OSPF into RIP using a route map based on a prefix list may not work for some routes. The show ip route network command shows that a network is not advertised by RIP.
Conditions: This symptom is observed when the prefix list is changed. The RIP database is not updated with the new network that was added to the prefix list.
Workaround: Issue the clear ip route network command.
•
Symptoms: Bursts of blank lines can be interspersed within the output from the show memory process command.
Conditions: The issue appears to be restricted to the output of this particular show command. The output may be influenced by other CLI commands being executed on the router.
Workaround: Avoid executing any commands on the router during the one-hour time period used to collect the output from the CLI show command.
•
Symptoms: An NSE-150 reloads unexpectedly when the show pxf crash command is entered.
Conditions: Router is running Cisco IOS Release 12.2(31)SB3 or a later rebuilt.
Workaround: Do not use the show pxf crash command. Cisco IOS Releases 12.2 (31)SB2 and earlier releases are not affected.
•
Symptoms: An NSE150 reloads because of a PXF crash on TMC1, Col 1, Row 2.
Impact: Operation of the network since router is loading.
Conditions: This symptom is observed when the router is running Cisco IOS Release 12.2(31)SB8.
Trigger: The crash is due to misaligned network_start. The concerned interfaces are tunnel204 and gig0.205. QoS pre-classify is configured on the tunnel.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 platform that is acting as an LNS crashes by bus error.
Conditions: The crash is seen in Cisco IOS Release 12.2(31)SB10 when the Cisco 10000 is applying the QoS configuration for the users.
Workaround: There is no workaround.
•
Symptoms: When you have maximum channels configured on a chstm1/choc12 card with more channels configured on ct3 card, the ac mgr process on the standby goes high during configuration download.
Conditions: This symptom is observed during configuration loads and link flaps.
Workaround: There is no workaround.
•
Symptoms: PPPoE sessions fail to come up.
Conditions: This symptom is observed only when an RBE and PPPoE are configured on the same ATM subinterface.
Workaround: Configure the no service pppoe-spoof-detect command to bring up a PPPoE session.
•
Symptoms: A user cannot use the redundant card once the router is reloaded with an APS configuration.
Conditions: Configure APS, reload the routers, and disassociate cards that are attached through APS CLI. Now the user cannot use the redundant card; sessions will not come up on that card.
Workaround: Enter a no card command followed by a card command to get the card back into a functional state.
•
Symptoms: "%INTERFACE_API-3-NODESTROYSUBBLOCK: The SWIDB subblock named SW FIB PENDING EVENT was not removed" error messages are observed on the router. This symptom does not affect traffic but may be the cause of a memory leak.
Conditions: This symptom is observed when PPPoE/L2TP sessions are established on Cisco 7300 routers. CSCsk38385 addresses this issue on Cisco 7200 routers.
Workaround: There is no workaround.
•
Symptoms: Downstream PPPoE session traffic over an ATM VC on an LNS is not shaped according to the applied policy map.
Conditions: This symptom is observed on standard PPPoEoA LNS session configurations. Passing traffic downstream and applying an HqoS policy on the egress interface, the session traffic is not shaped by the shaper configured on the VC.
Workaround: There is no workaround.
Further Problem Description: The shaping failure is the result of an output packet queue for the shaped traffic using the ATM subinterface instead of the ATM PVC.
•
Symptoms: This problem is internal only; it will not affect any functioning of the router; and it has no associated symptoms.
Conditions: The user would need to have a queueing policy map applied to an LNS session and then remove that policy map and replace it with a non- queueing policy map to create this case.
Workaround: There is no workaround.
•
Symptoms: Memory leak in SSS. SSS info element and SSS info list.
Conditions: QoS fails being deleted from the session and reports the failure to Session Manager (SM). Session Manager finishes cleaning up the session.
Workaround: There is no workaround.
Further Problem Description: When the TC feature is being deleted, it will send this SSS_INFOTYPE_SERVICE_REMOVED_KEY element key to SM in a notify event. By this time, SM has finished clearing this session and therefore cannot locate the SM context. SM will, in turn, display an error message:
Jan 17 09:28:31.816: SSS MGR: Bad Handle in Feature Msg, ID = 0x37000002And return without cleaning up both message and any transient data within the message.
•
Symptoms: Multilink bundles fail to come up.
Conditions: This problem will be seen only if the bundle has 10 members associated with it.
Workaround: Remove one member from the bundle, by removing the ppp multilink group command, and then do a shut/no shut of the bundle.
Further Problem Description: If we try to bring up a bundle that has 10 members, the bundle will fail to come up. If the bundle has less than 10 members, we will not see this issue.
•
Symptoms: The standby fails to come up in SSO. The following message is seen on the active:
%FILESYS-4-RCSF: Active running config access failure (0) <file size>Conditions: This symptom is observed when the router has a configuration greater than 0.5 megabytes.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 may see high CPU and/or CPUHOG error messages when doing a lawful intercept tap. This may also happen with an ACL configuration change that causes the ACLs to recompile.
Conditions: This symptom is observed when the tap and access lists are on a loopback interface.
Workaround: There is no workaround.
•
Symptoms: ifOutOctets and ifHCOutOctets are 0 and not being incremented for some Virtual Access interfaces.
Conditions: This symptom is observed on a Cisco 10000 router that is running Cisco IOS Release 12.2(31)SB6.
Trigger: Unknown.
Impact: Monitoring and troubleshooting of Virtual Access interfaces using SNMP are impacted.
Workaround: There is no workaround.
Further Problem Description: Interface counters as seen in the output from the show interface command are incrementing okay. ifInOctets and ifHCInOctets are incrementing. The problem is affecting only some Virtual Access interfaces, not all.
•
Symptoms: A router crashes when MPLS VPN configurations are applied.
Conditions: This symptom is observed with the following configuration:
Router(config-if)# interface a1/0.1 point-to-point
Router(config-subif)# mpls ip
Router(config-subif)# mpls label protocol ldp
Router(config-subif)# ip address 10.0.0.2 255.0.0.0
Router(config-subif)# no ipv6 address
Router(config-subif)# ip split-horizon
Router(config-subif)# pvc 6/100
Router(config-if-atm-vc)# encaps aal5snap
Router(config-if-atm-vc)# exit
Router(config-subif)# no shutWorkaround: There is no workaround.
•
Symptoms: A device keeps reloading every 50 minutes.
Conditions: The issue will occur only if the standby RP gets reloaded while CEF is part-way through synching initial data to the standby RP before standby hot state is reached in SSO mode.
Trigger: Removal or reload of standby before CEF initial synch is complete.
Impact: This issue affects operations.
Workaround: Reload the active PRE if this issue occurs.
•
Symptoms: A router crashes with "Address Error (load or instruction fetch) exception" when the show ip vrf vrf-name command is used.
Conditions: On one vty session, enter the show ip route vrf vrf-name command and leave it in the "more" condition. From other user interface session, go to configuration mode, and then enter the no ip vrf vrf-name command using the same VRF name. After at least 5 minutes, the router will crash after hitting the any key on the session that is doing the show ip vrf command.
Workaround: Make sure that there is no show ip route vrf command pending before entering the no ip vrf command.
•
Symptoms: A BRAS system might experience a crash when applying ACLs downloaded by RADIUS.
Conditions: This problem can happen during normal system operation and was seen once a week after deploying a special based on Cisco IOS Release 12.2(31)SB10.
Workaround: There is no workaround.
Further Problem Description: Another special still based on 12.2(31)SB3 did not show this problem.
•
Symptoms: A Cisco 7304 router that has redundant NSE-100 RPs and that is running Cisco IOS Release 12.2(31)SB10 or 12.2(31)SB11 may crash with the following message after a switchover:
tmc0 Crash Summary 0040 0300 XHXType :80000000 Global Halt 0040 0308 MACXID :00000008 External Column Memory 3 Exception 0040 0004 IHBXType :00000000 0040 0120 RPXType :00000000
%NSE100-3-ERRORINTR: Fatal error interrupt. IOFPGA error interrupt statuses : Asic/FPGA 0001, Line card 0000, OIR 0000, Envm. 0000Conditions: The crash will occur only upon inducing a switchover using the redundancy force-switchover command and under the following conditions:
1. Redundancy mode SSO.
2. Unicast RPF configured on ATM PVCs.
3. Traffic going out through the PVCs at the time of the switchover.
The problem does not occur when PXF is disabled (at the time of the switchover) using the no ip pxf command.
Workaround: Disable PXF just before the switchover; enable it once the old primary reloads successfully. This is because that is the window when the crash occurs.
•
Symptoms: After a PRE fails over to the standby, and then fails to the standby again, a PPP encapsulation interface bound to a PPP multilink interface that is not active will keep the interface status of the serial link Up/Down.
Conditions: Three things must be configured on the Cisco 10000 PRE2.
1. Redundancy mode SSO.
2. PPP encapsulation.
3. PPP multilink with the interface created.
The issue is with PPP multilink and using redundancy mode SSO.
Workaround: Remove the PPP multilink commands from the E1 interface, and remove the multilink interface. Then fail over to the standby.
•
Symptoms: A router crashes.
Conditions: Clearing PPPoE sessions while sessions are coming up with pushing policy maps via RADIUS results in a crash on the Cisco 10000.
Workaround: There is no workaround.
•
Symptoms: The ciscoEnhancedMemPoolMIB table is empty.
Conditions: This symptom is observed when a Cisco 7301 series router is loaded with Cisco IOS Release 12.2(31)SB11 and when SNMPget(getmany) is performed on the ciscoEnhancedMemPoolMIB.
Workaround: There is no workaround.
•
Symptoms: A BOOTP client does not receive a DHCPOFFER message from the server.
Conditions: This symptom is observed in Cisco routers that are loaded with Cisco IOS Release 12.5(0.11).
Workaround: There is no workaround.
•
Symptoms: A Gigabit interface on an NSE150 flaps.
Conditions: This symptom is observed under a high traffic load.
Workaround: There is no workaround.
Further Problem Description: This problem is usually caused by defective hardware (SFP, cable, NSE board). Those were swapped, and the problem persisted.
•
Symptoms: Concurrent operations on NVRAM can result in corruption of the configuration register on the secondary PRE3 or PRE4.
Conditions: Concurrent writes and reads to the NVRAM can cause bad data to be read. In the case of this bug, the configuration register is read while the system configuration is being written, and the wrong value is obtained. With HA, if the bad configuration register value is seen as a change and propagated to the secondary, this can result in a system configured for autoboot having its configuration register changed to 0, leaving the secondary at the ROMMON prompt after a reboot.
Workaround: There is no workaround.
Further Problem Description: Concurrent access, such as doing a "show bootvar" to read NVRAM while doing a "write" to write it, can cause this condition.
•
Symptoms: A Cisco ISG reloads when subscriber sessions have traffic classes.
Conditions: This symptom is observed when 1000 to 24,000 sessions go down and come up.
Workaround: There is no workaround.
•
Symptoms: A Cisco 7300 with an NSE-100 crashes.
Conditions: This symptom is observed if you configure a hierarchical policy map with a SET command in the second level. The "set" command is not supported in the second level policy in the PXF.
Workaround: Do not configure SET in the second level of a hierarchical policy map.
Further Problem Description: Because it is not a supported configuration, the router will not accept that configuration in the future.
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Symptoms: A Cisco 10000 series router may reload unexpectedly while applying service profiles to sessions.
Conditions: This symptom is observed when applying services that contain QoS parameters. The service that contains QoS must not be the first service that is applied. The router might display tracebacks that show that the aaa_attr handle is retired.
Workaround: There is no workaround.
•
Symptoms: An MLP PPP session is not installed into the correct VRF.
Conditions: This symptom is observed when the VRF is configured as peruser or service profile through the "ip:vrf-id ..." "ip:unnumbered ..." VSAs.
Workaround: Use the following:
lcp:interface-config=ip vrf forwarding <vrf> lcp:interface-config=ip unnumbered <loopback-interface>
•
Symptoms: It is a basic functionality breakage. Packets are not getting policed, so the show policy-map int command shows wrong counts. Conform and exceed actions are not being performed.
Conditions: Policing is not working in the MPLS cloud. Even though packets are getting classified correctly, policing is not working on those packets.
Workaround: There is no workaround.
Further Problem Description: Policing is not working in the MPLS cloud. Consider the following three scenarios:
1) When a service policy and MPLS are configured on the subinterface, policing works fine.
2) When a service policy and MPLS are configured on the main interface, policing works fine.
3) When a service policy is attached on the main interface and MPLS on the subinterface, policing does not work.
The first two cases work fine. It means if the MPLS feature and policy are on the main interface or the MPLS feature and policy are on the subinterface, policing works correctly. The problem is with the third case. Here, the MPLS feature is applied on the subinterface and policy on the main interface. If we do not have MPLS configured and we are receiving just IP packets, then all cases work fine. But MPLS packets are treated as IP packets.
•
Symptoms: LFI bundles will not come up.
Conditions: The commit of CSCsl98665 disturbed the single member bundle creation.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10008 PRE2 that is running an engineering special based on Cisco IOS Release 12.2(31)SB10 crashes and reloads because of a bus error.
Conditions: The Cisco 10000 has the following number of users:
–
–
Workaround: There is no workaround.
•
Symptoms: An ISG does not unapply the "credit-exhausted" service (i.e., the one that was applied upon event "credit-exhausted") if redirect was upon service-name matching.
Conditions: The step-by-step procedure is as follows:
Problem Case:
QT=0 , IT >0 apply L4RD , L4RD is NOT removed upon reauthorization , QT>0 , IT>0 Default-service installed
!
class type control cm-DEF_Inet event credit-exhausted
1 service-policy type service name DEF_Inet_L4RWorkaround: Change the class type control to "always" instead of "cm- DEF_Inet".
Working Case:
QT=0 , IT >0 apply L4RD , L4RD is removed upon reauthorization , QT>0 , IT>0 Default-service installed
!
class type control always event credit-exhausted
1 service-policy type service name DEF_Inet_L4R•
Symptoms: An (S,G) with low traffic might keep flapping. This (S,G) gets created and then 3 minutes later gets deleted. This (S,G) will keep getting created and deleted based on the traffic.
This issue can also be seen with an (S,G) corresponding to default MDT in MVPN scenario. This (S,G) will get deleted after 3 minutes but will reappear 30 seconds after the deletion, and the whole cycle continues.
Conditions: This symptom is observed on a Cisco 10000 that is running Cisco IOS Release 12.2(31)SB9. The traffic rate on this (S,G) has to be less than 1 packet per 10 seconds. The source for this (S,G) has to be a different router.
In the MVPN case, the Cisco 10000 has to be a PE that is configured for MVPN. In the (S,G), the S is a far-end PE and the G is an MDT group for some VRF. Also the traffic has to be less than 1 packet per 10 seconds.
Workaround: There is no workaround.
•
Symptoms: ISSU fails and numerous issues.
Conditions: This symptom is observed after the commit of CSCsj77305.
Workaround: There is no workaround.
•
Symptoms: A Cisco ISG is sending both QT and QV in prepaid reauthorization requests even though only time-based prepaid service is enabled. When the billing server responds with QT and QV, the ISG treats it as dual quota and drops the session.
Conditions: This symptom is observed when the Cisco ISG subscriber is enabled with time-only prepaid service.
Workaround: If the billing server can always send QV with a very high from beginning to in all reauth responses, then the ISG treats it as dual quota from beginning.
•
Symptoms: The reassembly index is not allocated after the bundles are flapped.
Conditions: This symptom is observed when an MLPoLNS multimember bundle is configured.
Workaround: To restore the bundle, enter the clear vpdn tunnel l2tp all command or the clear ppp interface command.
•
Symptoms: On a system where the access-list compiled command has been configured to enable Turbo ACL or on systems where Turbo ACL is always enabled, increased CPU utilization may be experienced because of Turbo ACL compilations being performed repeatedly.
Conditions: This symptom has been observed on a Cisco 7300 router (NSE100) that is running Cisco IOS Release 12.2(31)SB8.
This situation occurs only in rare circumstances based on the traffic received since the system booted. When this issue occurs, the output of the show processes cpu command may indicate that the "TurboACL" process is consuming a significant percentage of the CPU time, and in the output of the show access-lists compiled command, the "builds" counter increases quickly, approximately one or more times per minute. Additionally, in the pairs of values separated by slashes on the lines labeled "L1," "L2," and "L3" in the output of this command, for at least one of the pairs, the value to the left of the slash will be 90 percent or more of the value to the right of the slash.
Workaround: Note that it is expected that a number of builds will occur in quick succession when the system first starts receiving traffic. If the situation occurs, it will generally stop occurring after some time as additional traffic flows are received; but it may be possible to configure the no access-list compiled command followed by the access-list compiled command to stop the repeated recompilations.
However, on some systems, such as the Cisco 7304 router, the access- list compiled command is not available. Therefore, Turbo ACL cannot be switched off on the Cisco 7304 because the classification table generated by Turbo ACL code is used by QoS, NAT, and Security ACL to index into their own respective tables. That is the way these features have been designed on the Cisco 7304. On such systems, no workaround is available.
•
Symptoms: An address error crash occurs while running Cisco IOS Release 12.2 (31)SB11. Decodes indicate a Layer 4 redirect.
Conditions: The conditions under which this symptom occurs are not known.
Workaround: There is no workaround.
•
Symptoms: Traceback using redirection.
Conditions: Using redirection in ISG.
Workaround: There is no workaround.
•
Symptoms: An alternate PVC may go down if you reload the local PE line card 10 seconds after the remote PE line card.
Conditions: This symptom is observed with a Cisco 12000 router that is loaded with a Cisco IOS Release 12.0(32)sy0i image. The local PE is configured with 4xCT3, and the remote PE is configured with 1xSTM1 and L2TPv3.
Workaround: Reload with a long delay between the local and remote PE's LC.
•
Symptoms: Billing fails for users.
Conditions: AAA accounting records are missing attribute 8 for Framed-IP- Address only for stop records of a service profile. The following is an example of what to look for:
4d22h: RADIUS(000000FC): Send Accounting-Request to 10.239.89.25:1813 id 1646/176, len 253
4d22h: RADIUS: Acct-Session-Id [44] 18 "0E00000000000FF5"
4d22h: RADIUS: ssg-service-info [251] 14 "NO00600_KBF0"
4d22h: RADIUS: Cisco AVpair [1] 36 "parent-session- id=0E00000000000FE6"
4d22h: RADIUS: User-Name [1] 14 "XXXXXXXXXXXXXX"
4d22h: RADIUS: Acct-Status-Type [40] 6 Stop [2]
4d22h: RADIUS: Framed-IP-Address [8] 6 X.X.X.X <<< missing attributeYou can tell it is a service accounting record when you see parent-session- id.
Workaround: Enable AAA accounting for the session as well as for the services.
•
Symptoms: A router might crash when the show idb command is issued.
Conditions: The crash is seen when the show idb command is issued after a large number of PPPoE sessions (for example, 6000 sessions) are initiated and cleared. The crash is seen with IPv6, but it is not seen with IPv4.
Workaround: There is no workaround.
•
Symptoms: The card type configuration disappears from active, whereas the corresponding interface configurations still show up. This results in a mismatch of configuration sync to the standby, and the standby is rebooted.
Conditions:
–
–
–
–
–
–
Workaround: To avoid the sync mismatch, add the corresponding card type configuration.
Further Problem Description: This problem was due to a wrong piece of code that used to remove the card configuration (if the earlier inserted card was not present) after a switchover on the new active. Whereas the standby was made to escape this check to take care of another race condition. This caused the configuration sync mismatch, resulting in standby reboot.
•
Symptoms: On a ds3atm line card, modifying dsx3mode from plcp to adm or vice versa on one ATM port causes the PVCs on all other ports to go down.
Conditions: This symptom is observed when dsx3mode is modified from plcp to adm or vice versa.
Workaround: Remove all PVCs and redefine them, or reload the line card.
•
Symptoms: A Cisco 10000 that is running ISG configurations could potentially experience instabilities.
Conditions: This symptom is observed with releases that have the fix for CSCek50693.
Workaround: There is no workaround.
•
Symptoms: When performing a ROMMON upgrade, operations that cause the Cisco IOS software to call ROMMON may cause the PRE3 or PRE4 to crash.
Conditions: This condition is observed when using the upgrade rom Cisco IOS command and performing operations that call ROMMON, including the show bootvar command or the boot system command.
Workaround: There is no workaround.
Further Problem Description: If the board hangs while upgrading the ROMMON, it may be necessary to power-cycle the PRE to regain control of it, and it will likely fall-back to the original rom0 image shipped with the board.
•
Symptoms: Build Breakage.
Conditions: Unable to compile legacy_hc_counter.o in 64-bit platform directory.
Workaround: There is no workaround.
•
Symptoms: Acct-Octets, Acct-packets, IO and OO attributes are not sent in prepaid accounting records for time-only prepaid service.
Conditions: This symptom is observed when time-only prepaid service is enabled on the ISG.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 router may enter a state of virtual perpetual churn in which calls continuously fail to come up.
Conditions: This symptom is observed during aggressive PPPoA call-in.
Workaround: There is no workaround.
•
Symptoms: A router crashes.
Conditions: This symptom is observed when:
–
–
Workaround: There is no workaround.
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Symptoms: GRE tunnels with a certain output policy cannot CEF-switch the punted traffic.
Conditions: If the GRE tunnel has an output policy with set configured, CEF switching does not work.
Workaround: Turn off CEF switching on the tunnel interface using the no ip route-cache cef command. However, this lowers the router performance.
•
Symptoms: A router crashes when trying to bring up thousands of PPPoA sessions.
Conditions: This symptom is observed when there are thousands of PPPoA sessions going up and coming down at the same time. This can happen when all sessions are cleared from the router.
Workaround: There is no easy workaround. When all PPPoA sessions go down, it is better to bring them up in a phased manner. Shut all ATM interfaces with PPPoA sessions and unshut them one by one.
•
Symptoms: Polling cvpdnSessionAttrDevicePhyId from the CISCO-VPDN-MGMT MIB may show that multiple users are mapped to the same Virtual-Access SNMP ifIndex. This affects statistics collection or billing using IF-MIB counters.
Conditions: This symptom is observed when PPP renegotiates an existing PPP connection on a Virtual-Access interface.
Workaround: When possible, use RADIUS accounting for gathering statistics or billing.
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Symptoms: On a Cisco 7300 series router while doing a switchover with the following HSRP configuration, the new secondary router reloads continuously with the following error message.
HSRP:Gi0/0.801 Grp 1 RF Encode data descriptor failedConditions: This symptom is observed in a GLBP/HSRP environment. It occurs only on the native Gigabit Ethernet or Fast Ethernet interface of a Cisco 7300 series router.
Frequency: Easily reproducible.
Trigger: Switchover.
Impact: The standby reloads continuously.
Workaround: Upgrade the Cisco IOS software.
The GE/FE ports on the standby NSE-100 and GE ports on the NPE-G100 on the Cisco 7300 do not have SSO capability. That is, these ports will flap when the system undergoes a switchover. Only these interfaces on a Cisco 7300 are affected.
•
Symptoms: A VC associated with a VT keeps flapping.
Conditions: This symptom is observed when LFIoATM is configured on a Cisco 7200 or when dLFIoATM is configured on a Cisco 7500 router.
Workaround: There is no workaround.
•
Symptoms: When using hierarchical shaping, a class queue in a child policy map (CBWFQ) does not give the minimum guaranteed rate (bandwidth rate).
Conditions:
–
–
–
Workaround: There is no workaround.
•
Symptoms: In a PRE2, high latency is observed in the MLP bundle link for the non-priority queue traffic.
Conditions: This symptom is observed under the following configurations:
–
–
–
–
Workaround: In global configuration mode, configure both the priority-queue and the non-priority-queue threshold values to 2.
1. ip pxf bfifo-threshold priority-queue 2
2. ip pxf bfifo-threshold non-priority-queue 2
Further Problem Description: CSCso29879 is not a bug, and an option has been provided to manipulate the bundle FIFO queue length for the priority queue and non-priority queue. When the threshold is set to lower values, the latency will be lower.
Default values for the bundle FIFO threshold for the priority queue and non- priority queue are 6 and 16, respectively. It is recommended that the bundle FIFO queue threshold be left at the default values.
•
Symptoms: If GLBP is configured on the native Gigabit Ethernet interface of a Cisco 7300, the router will continually reload if an HA switchover is performed.
Conditions: This problem affects only the native Gigabit Ethernet interface of a Cisco 7300 because this hardware does not support HA.
Workaround: There is no workaround.
•
Symptoms: An align traceback may be generated on a Cisco 10000 series.
Conditions: This symptom is observed when a 4-port channelized T3 half-height comes up with a huge configuration.
Workaround: There is no workaround.
•
Symptoms: L4-redirect intermittently fails. CoA Nack is returned to the redirection server.
Conditions: These symptoms can occur in a high-traffic situation in which many requests need to be handled by the ID manager database.
Workaround: Reload the router running ISG.
•
Symptoms: In a Cisco 7304 NSE-100, traffic shaping is broken. It is dropping more than 50 percent of the shaped rate.
Conditions: This symptom is observed on a Cisco 7304 router with an NSE-100 or NSE-150 when an interface is configured with a service policy with parent shaping.
Workaround: There is no workaround.
Fix Details: The fix for this issue does not cover CBWFQ with a shaping rate less than 4 mbps. To track this specific case, CSCsq19176 has been filed.
•
Symptoms: L4-redirect intermittently fails. CoA Nack is returned to the redirection server. Dangling records (records for non-existent session) exist in the idmgr database.
Conditions: The conditions under which this symptom is observed are unknown.
Workaround: Reload the router that is running ISG.
Open Caveats—Cisco IOS Release 12.2(31)SB11
Cisco IOS Release 12.2(31)SB11 is a rebuild release for Cisco IOS Release 12.2(31)SB. This section describes caveats that are open in Cisco IOS Release 12.2(31)SB. There are other open caveats in Cisco IOS Release 12.2(31)SB11. However, open caveats are normally listed only for maintenance releases, and the listing of these caveats is an exception.
IP Routing Protocols
•
Symptoms: Multilink bundles fail to come up.
Conditions: This problem will be seen only if the bundle has 10 members associated with it.
Workaround: Remove one member from the bundle, by removing the ppp multilink group command, and then do a shut/no- shut of the bundle.
Further Problem Description: If we try to bring up a bundle that has 10 members, the bundle will fail to come up. If the bundle has less than 10 members, the issue is not seen.
Resolved Caveats—Cisco IOS Release 12.2(31)SB11
Cisco IOS Release 12.2(31)SB11 is a rebuild release for Cisco IOS Release 12.2(31)SB. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB11 but may be open in previous Cisco IOS releases.
IP Routing Protocols
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Symptoms: The Generalized TTL Security Mechanism (GTSM), formerly known as BGP TTL Security Hack (BTSH), checks the time-to-live (TTL) value of the packets at the application level, which is not efficient. Also, GTSM does not stop the establishment of a TCP connection for a packet with an invalid TTL value.
Conditions: This symptom is observed on a Cisco platform that has the neighbor neighbor-address security ttl hops hop-count command configured in a BGP environment.
Workaround: There is no workaround.
•
Symptoms: Spurious memory accesses occur on a Cisco 7200 series and ALIGN-3-SPURIOUS error messages are generated.
Conditions: This symptom is observed on a Cisco 7200 series that processes traffic through a serial interface.
Workaround: There is no workaround.
•
Symptoms: Filtering BGP routes by means of the distribute-list prefix MARTIAN in command applied to address-family ipv4, actually filters out M-BGP routes in address-family vpnv4.
Conditions: This symptom occurs when MPLS-VPNs are configured.
Workaround: Use route-maps to filter routes inbound.
Further Problem Description: It can be checked by means of the show ip bgp neighbors command that the prefixes are actually being filtered out from updates for address-family vpnv4, and not for ipv4, as it is configured.
•
Symptoms: A router that is configured for NAT may crash.
Conditions: This symptom is observed when an application uses two well-known ports: one for the source and the other for the destination. After the outgoing translation is created, on return, when the previous source port is used as the destination, NAT may use an incorrect algorithm.
For example, when a PPTP session is initiated to well-known port 1723 from source port 21 (FTP), then the outgoing packet creates a FTP translation. (Look at the source information when going from in to out). When the packet is returned, look again at the source information to see what kind of packet is returned. In this situation, with source port 1723, NAT assumes that the packet is a PPTP packet, and then attempts to perform PPTP NAT operations on a data structure that NAT has built for a FTP packet, causing the router to crash.
Workaround: There is no workaround.
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Symptoms: A router crashes when you unconfigure and then reconfigure MLPoFR.
Conditions: This symptom is observed on a Cisco router that has a QoS service policy with traffic shaping.
Workaround: There is no workaround.
•
Symptoms: Router crashes on watchdog timeout.
Conditions: This symptom occurs when deleting lots of interfaces with the interface range command.
Workaround: There is no workaround.
•
Symptoms: When you deactivate an ATM PVC, an "ALIGN-3-SPURIOUS" error message may be generated on the console.
Conditions: This symptom is observed when the ATM PVC is carrying PPPoA sessions.
Workaround: Deactivate the PPPoA sessions before you deactivate the ATM PVC.
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Symptoms: A service policy is unexpectedly removed.
Conditions: This symptom is observed when you apply a service policy to a multilink interface and then the interface is reset.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, reconfigure the service policy after the multilink interface has been brought up.
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Symptoms: In standby the following commands are not displayed when viewing running configuration:
connect atom_1 POS4/0 500 l2transport
xconnect 9.0.0.3 100 encapsulation mpls
Conditions: This symptom occurs on a Cisco 7600 router.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series router may reload unexpectedly with COMMON_FIB- 2-IF_NUMBER_ILLEGAL tracebacks.
Conditions: This symptom was observed when bringing up a large number of mixed PTA and L2TP sessions. The system is on SSO mode of High Availability.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series router may experience CPUHOG condition.
Conditions: This condition is observed when there is an increase of more than 2000 sessions established.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series router may reload unexpectedly during aggressive PPPoA call bringup.
Conditions: This symptom is observed in system test on a Cisco 10000 series router that is running Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series router may reload unexpectedly during aggressive PPPoA call bringup.
Conditions: This symptom is observed in system test on a Cisco 10000 series router that is running Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series router may reload unexpectedly during aggressive PPPoA call bringup.
Conditions: This symptom is observed in system test on a Cisco 10000 series router that is running Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
•
Symptoms: By default, dot1q subinterfaces do not report link up/down conditions via SNMP traps. While this can be changed using the snmp trap link-status interface configuration command on the subinterface, this command is not retained upon reloading the device.
Conditions: This problem has been observed on Cisco 1721, Cisco 2620 and Cisco 2621XM routers that are running Cisco IOS Release 12.3(13a), Release12.4(3), or Release 12.3(14.12), but other platforms may also be affected.
Workaround: Reapply the snmp trap link-status interface configuration command after the device has been restarted.
•
Symptoms: SNMP polls hang at a specific point, after which there is no response for a long time. Then, SNMP polling works fine for a while until it hangs again at a specific point.
When SNMP becomes unresponsive, the following error message may be generated, and SNMP queries may time-out at the application:
%SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input queue fullConditions: These symptoms are observed under the following conditions:
–
–
Workaround: Exclude the CISCO-ENHANCED-MEMORY-POOL-MIB from the SNMP view. Enter the following commands to exclude the CISCO-ENHANCED-MEMORY-POOL-MIB:
snmp-server view public-view iso included
snmp-server view public-view ciscoMemoryPoolMIB excluded
snmp-server view public-view ciscoEnhancedMemPoolMIB excluded
snmp-server community public view public-view ROThis view should be applied to all community strings that might be used to poll these MIB modules. If views are already applied to a community string then the one above and the existing view should be merged.
If SNMPv3 is in use then this view should be applied to any SNMPv3 groups configured as well.
There is no need to reboot the platform. The symptom should resolve itself within a few minutes. If you must immediately clear the symptom, enter the following two commands (use one of the SNMP server community string commands that are actually configured on the router instead of the ones that are mentioned in the example below, which are based on the information that is presented above):
Disable SNMP and stop the processes:
no snmp-server
Re-enable SNMP and restore the SNMP configuration:
snmp-server community public view public-view ROFurther Problem Description: When you enable the debug snmp packet command, you can see that the SNMP poll requests are not being acknowledged. However, the output of the show snmp counters command shows about the same number of SNMP requests as the number of outputs, even though these outputs were never processed and sent.
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Symptoms: Crash is seen on Standby Route Processor.
Conditions: The crash is normally seen in case of unnumbered relay, when Standby Relay gets synced from Active Relay. The crash is showing some data inconsistency issue while the Standby Relay gets synced.
Workaround: There is no workaround.
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Symptoms: A router may reload when Border Gateway Protocol (BGP) neighbor statements are removed from the configuration.
Conditions: This symptom is observed in rare circumstances on a Cisco router when BGP neighbors are removed very quickly by a script at a much faster rate than manually possible and when a large BGP table is already present on the router before the script adds and removes the BGP neighbors.
Workaround: There is no workaround.
Further Problem Description: If you manually remove the BGP neighbors, it is less likely that the symptom occurs.
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Symptoms: When BGP updates are received, stale paths are not removed from the BGP table, causing the number of paths for a prefix to increase. When the number of BGP paths reaches the upper limit of 255 paths, the router resets.
Conditions: This symptom is observed on a Cisco router when the neighbor soft-reconfiguration inbound command is enabled for each BGP peer.
Workaround: Remove the neighbor soft-reconfiguration inbound command. A router that runs a Cisco IOS software image that has a route refresh capability, storing BGP updates is usually not necessary.
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Symptoms: When a Cisco router that has redundant RPs that function in RPR+ or SSO mode is reloaded, the standby RP may not boot correctly and may continuously reload.
Conditions: This symptom is observed on a Cisco router that is configured for BGP and that has an IPv4 MDT address family. The symptom occurs because of configuration synchronization issues that are related to the IPv4 MDT address family.
Workaround: There is no workaround.
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Symptoms: The SNMP input and output counters may not be incremented or may show a wrong value.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 and a POS interface that is configured for Frame Relay encapsulation.
Workaround: Do not use SNMP for information about the input and output counters. Rather, enter the show frame-relay pvc command.
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Symptoms: Cisco IOS crash is observed when removing PCMCIA flash card.
Conditions: This crash can occur when the flash card is removed during a read to the card.
Workaround: Do not remove flash card when it is in use.
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Symptoms: When NetFlow attempts to access a FIB source that is not present in the FIB, the router may crash.
Conditions: This symptom is observed on a Cisco router that is configured with VLAN interfaces and virtual templates when a FIB source that is related to a virtual interface is not present in the FIB because of severe interface flaps.
Workaround: There is no workaround.
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Symptoms: When you boot the platform, the supervisor engine and a line card may crash during the "label_entry_get_inlabel" process.
Conditions: This symptom is observed on a Cisco Catalyst 6500 series switch and Cisco 7600 series router that are configured for MPLS.
Workaround: There is no workaround.
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Symptoms: An accounting record may indicate that the NAS-Port-Id has an adapter number of 1 when the correct adapter number is greater than 1.
Conditions: This symptom is observed when AAA accounting is configured and a PPP interface that is used as a NAS port has more than two adapters.
Workaround: There is no workaround.
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Symptoms: A router crashes when QoS is configured on POS and traffic line rate is sent.
Conditions: This symptom is observed when QoS and above line rate traffic.
Workaround: Remove QoS.
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Symptoms: A spurious memory access message like this one:
%ALIGN-3-SPURIOUS: Spurious memory access made at 0x62228B5C reading 0x18
%ALIGN-3-TRACE: -Traceback= 62228B5C 61355F34 613560C8 607172BC 60732490 6083976C 60839758 00000000is displayed on the console of the router when you configure a class map under the frame-relay interface-dlci statement of a MFR bundle and that this class map has not been defined yet, and there is already an output queuing policy attached to an other class map, which is already attached to the MFR bundle.
Conditions: This symptom happens only if there is already an output queuing policy attached to another class map attached to the MFR bundle and the class map you try to attach does not exist yet.
Workaround: There is no workaround.
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Symptoms: Local switching connection will not pass traffic after microcode reload in a router.
Conditions: This issue occurs when a user does a microcode reload with local switching connection configured.
Workaround: Delete the connection and configure it again.
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Symptoms: User is not able to configure AToM Xconnects on interfaces that use PA-POS-1OC3 cards. The following error message is displayed:
MPLS encap is not supported on this circuitConditions: Xconnects cannot be configured only when PA-POS-1OC3 cards are used.
Workaround: There is no workaround.
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Symptoms: When F4 QoS model is configured, that is VLAN is shaped, and PPPoEoVLAN sessions are configured with hierarchical policy-map (top shaping, child PQ/CBWFQ), and traffic is generated, the policy-map attached for VLAN shaping counters show all zeroes. With no broadband case, policy-map attached at VLAN shows counters as non-zeros.
pumoni-1#show policy-map int
TenGigabitEthernet1/0/0.1
Service-policy output: pm_vlan_shaper
Class-map: class-default (match-any)
0 packets, 0 bytes
30 second offered rate 0 bps, drop rate 0 bps
Queueing
queue limit 25000 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 0/0
shape (average) cir 1000000000, bc 4000000, be 4000000
target shape rate 1000000000Conditions: This problem is seen with both 10GE and 1GE.
Workaround: There is no workaround.
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Symptoms: After clearing PPPoEoVLAN session, applying a HQoS policy on the VLAN fails.
Conditions: This issue occurs on a Cisco 10000 series router with PRE3 board. A session comes up on a VLAN/QinQ, and HQoS is applied to that session. When the session is removed, applying a HQoS policy on the VLAN/QinQ fails.
This only occurs if the session parent policy is configured with "bandwidth remaining ratio x".
Workaround: There is no workaround.
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Symptoms: A Cisco 7200 series may crash when you perform a soft OIR of a port adapter.
Conditions: This symptom is observed when Frame Relay encapsulation is configured along with QoS on a PA-4T+ port adapter. However, the symptom is not specific to the PA-4T+ port adapter.
Workaround: There is no workaround.
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Symptoms: COA client sends message to the COA server (BRAS). NAS is unable to identify subscriber session when COA client and subscriber are on different VRFs.
Conditions: This symptom occurs when the COA client (RADIUS server) is on a VRF which is different from the subscriber sessions VRF.
Workaround:
1.
2.
Further Problem Description: Fix for the bug allows for specifying the VRF on which subscriber session is present.
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Symptoms: NAS crashes when sending invalid account session ID.
Conditions: None.
Workaround: There is no workaround.
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Symptoms: An unexpected PXF crash occurs after showing the following error messages:
Sep 2 17:48:20 BST: %C10KEVENTMGR-4-PXF_CRASHINFO: Writing PXF debug
information to bootflash:pxf_crashinfo_20070902-164820.
Sep 2 17:48:24 BST: %C10KEVENTMGR-1-MAJOR_FAULT: PXF DMA OQC at End of
Descriptor With Non-Zero Continuation Bit, Restarting PXFConditions: This symptom is happening several times in a Cisco 10000 series router that is running Cisco IOS Release 12.2(31)SB6, with no changes or interaction with the box at the moment of the crash. This symptom is seen on a Cisco 10000 series router that is acting as a LNS device in a broadband configuration.
Workaround: There is no workaround.
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Symptoms: There is possible memory corruption during routemap deletion.
Conditions: This symptom occurs when BGP is running.
Workaround: There is no workaround.
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Symptoms: A router crashes on removing encapsulation from ATM subinterface when bundle is up.
Conditions: This symptom is observed on a Cisco 10000 router with MLPoATM/MLPoLNS up.
Workaround: There is no workaround.
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Symptoms: A Cisco 7500 series router that is running Cisco IOS Release 12.2SB and Release 12.0S continues to witness output drops after configuring and unconfiguring an Output Policy containing Police feature on a Logical Interface. On a Cisco 7507 router that is running Cisco IOS Release 12.0(32) S9, reconfiguring fair-queue causes the VIP crash by signal = 10.
Conditions: The problem is caused when installing a policy with police on a logical interface: Subinterface, ATM PVC, Frame Relay DLCI, etc. After removal of such policy, the interface continues to police traffic. If the interface is configured with FR and the fair-queue is reconfigured, the VIP crashes.
Workaround: There is no workaround. The router has to be reloaded to correct the behavior.
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Symptoms: A Cisco 10000 router may crash when sessions are being established/torn down with sessions using per-user access-lists applied via RADIUS.
Conditions: This symptom is observed with sessions with per-user ACLs.
Workaround: There is no workaround.
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Symptoms: All frames received on gigabit ethernet interface are dropped. All drops are reported as overruns in the output of show interfaces and show controllers.
Conditions: Symptom is observed on gigabit ethernet interfaces on NPE-G2 network processor of Cisco 7200 Series Routers. All IOS trains that support NPE-G2 are affected.
Symptom is observed only when the gigabit ethernet controller is in promiscuous mode and with moderate traffic rate. Line protocol on the interface remains up when the error condition is present.
Workaround: There is no workaround. When the gigabit controller falls into this condition, the only way to recover is to power-cycle the router. Soft reload does not clear the problem.
Further Problem Description: Ethernet controller goes into promiscuous mode under two conditions:
–
–
The latter case may happen when a large number of HSRP groups is configured or a large number of IP multicast groups are to be received on the interface.
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Symptoms: HA sync message handling of InARP map results in buffer overflow copy.
Conditions: This issue is seen only in HA test scenario and also with large Subif I/F name and large VPI/VCI number.
Workaround: Use the small number for Subif and VPI/VCI.
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Symptoms: The multilink interfaces are going down while running LFIoFR.
Conditions: This symptom is seen when configuring LFIoFR. Verify everything is working fine and follow these steps:
–
–
–
–
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–
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Workaround: There is no workaround.
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Symptoms: A router crashes when scaling to 1000 eBGP sessions and flaps the interfaces.
Conditions: This symptom happens when there is a lot of hash collisions as routes are deleted.
Workaround: There is no workaround.
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Symptoms: Outbound L2VPN traffic does not flow over Ethernet interface on Cisco 10000 router.
Conditions: This symptom is observed when a PE router reloads.
Workaround: Disable CDP on the interface.
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Symptoms: In Cisco 10000 series router with a two-level policy, adding queue- limit to the class-default of the parent policy is an invalid configuration if the child has queuing features. It should be blocked.
Conditions: There should be a hierarchical policy-map with child having queueing features like bandwidth, queue-limit, priority. With child policy attached to class-default of parent, adding queue-limit to class-default of parent-policy is an illegal configuration.
Workaround: There is no workaround.
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Symptoms: Traffic is not flowing after SSO switchover when active APS ATM card is shut on an APS pair.
Conditions: This symptom occurs after SSO switchover when active APS ATM card is shut on an APS pair. Traffic is not flowing.
Workaround: There is no workaround.
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Symptoms: When the maximum-paths n import command is unconfigured, for example, a no maximum-paths n import m command is issued for a VPN/VRF on a router, sometimes the routes in that VPN may have duplicate path entries.
For example:
diezmil#sh ip bgp vpnv4 v v1001 4.2.20.0
BGP routing table entry for 100:1001:4.2.20.0/24, version 1342275
Paths: (2 available, best #1, table v1001)
Flag: 0x420
Not advertised to any peer
65164, imported path from 100:1:4.2.20.0/24
192.168.7.7 (metric 4) from 192.168.5.5 (192.168.5.5)
Origin IGP, metric 1552, localpref 80833, valid, internal, best
Extended Community: RT:100:1001
Originator: 192.168.7.7, Cluster list: 192.168.5.5
mpls labels in/out nolabel/291
65164, imported path from 100:1:4.2.20.0/24
192.168.7.7 (metric 4) from 192.168.5.5 (192.168.5.5)
Origin IGP, metric 1552, localpref 80833, valid, internal
Extended Community: RT:100:1001
Originator: 192.168.7.7, Cluster list: 192.168.5.5
mpls labels in/out nolabel/291Workaround: The least resource-intensive workaround is to configure and unconfigure a dummy import map under that VPN/VRF. Clearing the affected BGP sessions on PEs also resolves the issue.
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Symptoms: Tracebacks and the following error message are seen:
%SYS-3-INTPRINT: Illegal printing attempt from interrupt level.Conditions: This symptom is observed on a Cisco 7304 router that is running Cisco IOS Release 12.2(31)SB8. QoS is configured. The configuration for a particular policy map total bandwidth is greater than the configured or reserved bandwidth for the interface on which the policy map is applied.
Workaround: There is no workaround.
Further Problem Description: Service policy is not applied to the interface as expected, no interruption for the router operation.
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Symptoms: Incorrect Account Name is shown in accounting records when TAL is configured.
Conditions: This symptom occurs when a service name is pushed onto a session, and no attribute 1 string is configured in the user profile.
Workaround: Configure an attribute 1 string in the user profile.
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Symptoms: "May_suspend" traceback messages are seen when a child policy is removed:
%SYS-2-INTSCHED: 'may_suspend' at level 7Conditions: This symptom occurs with large configurations when there are many interfaces using the same policy.
Workaround: There is no workaround.
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Symptoms: QoS policy counters do not record all the packets in matching class.
Conditions: This symptom is observed on a Cisco 7300 series router with NSE- 150 and Cisco IOS Release 12.2(31)SB8.
Workaround: There is no workaround.
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Symptoms: When executing the show aaa attribute protocol radius command, a router that is running Cisco IOS may crash or output junk characters.
Conditions: This symptom is seen in images beginning with Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround.
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Symptoms: PPP renegotiates on the far end router when it receives a CONFREQ from the head end router during a PRE failover on the head end router. SSO state was verified prior to the PRE failover on the head end router.
Conditions: This symptom is observed in Cisco IOS Release 12.2(28)SB4c and Release 12.2(28)SB10. It was also seen in first engineering image Cisco IOS Release 12.2(28)ZX.
Workaround: There is no workaround.
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Symptoms: Router crashes when scaling to 2000 eBGP sessions.
Conditions: This symptom occurs when route tables are deleted and inserted frequently.
Workaround: There is no workaround.
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Symptoms: Lawful Intercept tapped PPPoE LCP/PPP control packets originating from the router contain incorrect payload.
Conditions: This symptom is observed on a Cisco 10000 router with radius based Lawful Intercept.
Workaround: There is no workaround.
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Symptoms: VC queues are starved.
Conditions: This symptom occurs when one or more shaped-UBR VCs experience traffic congestion. The other VCs that are configured on the same port can experience starvation, causing low link utilization on the port. This problem is seen on PRE3 but not on PRE2.
Workaround: Use unshaped-UBR, CBR or VBR-shaped VCs rather than shaped-UBR.
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Symptoms: The LI tapped PPPoEoA packets show 4 extra bytes for incoming tapped packets and 8 for outgoing tapped packets sent/received over a 4-OC3 ATM port. These bytes are sitting in between the intercept-ID and the SNAP header. Normally, the intercept-ID should be followed immediately by SNAP header.
Conditions: This symptom is observed on a Cisco 10000 series router with 4-OC3 ATM port, and QoS service is applied via ISG.
Workaround: Do not have the QoS service applied via ISG.
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Symptoms: Multilink interfaces fail to come up for LFIoFR after router bootup.
Conditions: Multilink bundles fail to come up for LFIoFR configuration.
Workaround: There is no workaround.
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Symptoms: When ISG is configured as a DHCP relay and the DHCP client is rebooted or if the DHCP client sends a DISCOVER packet in error, ISG is unable to process subsequent DISCOVER packets.
Conditions: This symptom occurs when ISG is configured as a DHCP relay, and the DHCP client is either rebooted or sends a DISCOVER packet in error.
Workaround: Configure ISG as a DHCP server.
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Symptoms: A Cisco 10000 series router may reload unexpectedly during aggressive PPPoA call bringup.
Conditions: This symptom is observed in system test on a Cisco 10000 series router that is running Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
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Symptoms: Summary address is not advertised via virtual-access interface.
Conditions: This symptom is observed when connecting and disconnecting the sessions.
Workaround: There is no workaround.
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Symptoms: A router crashes when IPv6 tables have a large number of entries. A traceback can also be seen.
Conditions: This symptom is seen when IPv6 route tables have a large number of entries. If we delete and insert routes in large number, like flapping interface and flapping BGP sessions, we may experience a router crash or traceback.
Workaround: There is no workaround.
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Symptoms: Standby PRE goes to hung state. Active PRE is not able to reset the Standby.
Conditions: This symptom occurs when hw-module |pre {a|b}| shut is configured or the hw-module standby reset hold command is issued in Active PRE.
Workaround: Reload of Active PRE.
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Symptoms: The throughput of the ATM PVCs is lower than expected.
Conditions: This symptom occurs on a Cisco 10000 router with PRE3 RP board if the user has configured a low burst value on a high speed VC.
Workaround: Configure a higher burst value for the VC.
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Symptoms: Packet statistics are not shown in the queue on a LAC session.
Conditions: This symptom is seen on a Cisco 10000 router after a PFX microcode reload only.
Workaround: There is no workaround.
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Symptoms: Delete an interface which has ip summary-address rip configured. The router crashes.
Conditions: In the scenario where different summary addresses are configured for different interfaces, if we delete an interface that has a summary-address configuration which is the last one for that summary-address that it leads to.
Workaround: Remove the ip summary-address rip configuration from an interface which is going to be deleted.
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Symptoms: PXF crashes seen with TCAM parity errors.
Conditions: These crashes will happen when:
1.
2.
Workaround: There is no workaround.
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Symptoms: Feature push for VRF-tx does not work.
Conditions: On the service profile, a "vrf-id=..." is configured. this is pushed onto a session. This attribute is ignored.
Workaround: Instead of doing the push through the RADIUS server, do the push using the SESM.
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Symptoms: The router may crash with a bus error while executing the show ip arp interface-name command.
Conditions: This symptom occurs when two executive processes are initiated by two different telnet sessions. One process is doing show ip arp interface while the other process is doing no ip address or ip address ip address under the configuration mode. Both commands are accessing the same interface. There is a chance that the show ip arp command will cause the system crash.
Workaround: Execute the show ip arp interface command and the ip address command configuration sequentially.
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Symptoms: ARP HA CPU tracebacks may be seen on the STANDBY PRE while it is booting up.
Conditions: This symptom is seen under extreme cases of large ARP tables. The Cisco 10000 router could generate ARP HA tracebacks on the STANDBY PRE while it is booting up.
Workaround: There is no workaround.
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Symptoms: Standby PRE might reset at bootup while trying to sync over large ARP tables from the primary to the standby PRE.
Conditions: The issue has been seem with very large (12 MB) configurations and large ARP tables (16K entries). The issue is only seen when the standby is booting up to standby mode.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB10
Cisco IOS Release 12.2(31)SB10 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB10 but may be open in previous Cisco IOS releases.
Basic System Services
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Symptoms: Password information may be displayed in a Syslog message as follows:
%SYS-5-CONFIG_I: Configured from scp://userid:password@10.1.1.1/config.txt by consoleConditions: When using SNMP to modify a configuration by means of the CISCO-CONFIG-COPY-MIB, selection of ConfigCopyProtocol of SCP or FTP may result in the password being exposed in a syslog message.
Workaround: When using SNMP to modify a configuration by means of the CISCO-CONFIG-COPY-MIB, use the ConfigCopyProtocol of RCP to avoid exposure of the password.
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Symptoms: Missing interim accounting requests for Traffic Class.
Conditions: When the interim accounting is configured and with the Traffic class attribute.
Workaround: There is no workaround.
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Symptoms: CPU HOG is reported because of SNMP engine while processing GetBulk of ciscoMemoryPoolEntry.7.3.
Workaround: Exclude ciscoFrameRelayMIB from polling if applicable.
Interfaces and Bridging
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Symptoms: A Cisco 7200 series that is configured for ATM and QoS may crash.
Conditions: This symptom is observed when you attempt to change the priority parameters while traffic is being processed.
Workaround: There is no workaround.
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Symptoms: The Gigabit controller of NPE-G2 board seems to not correctly recognize the QinQ encapsulation, dropping the packets as giants.
The packets with the double encapsulation above 1496 bytes are not passing through, being dropped at the input of the NPE-G2 as giants.
Reverting to single encapsulation on both sides the behavior returns as expected, allowing the ping with any size.
The DF-bit has never been used during the tests.
Conditions: This symptom is observed on a Cisco 7200 series router that is running Cisco IOS Release 12.2(31)SB7.
Workaround: Configure the L2 interface MTU to 1504 instead of 1500.
IP Routing Protocols
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Symptoms: An MDT address-family session in a BGP environment may not come up between two PE routers. This situation prevents the tunnel interface from being shown in the output of the show ip pim vrf vrf-name neighbor command on one of the PE routers.
Conditions: This symptom is observed on PE routers that are configured for Multicast VPN and that have the following commands enabled:
address-family ipv4 mdtneighbor neighbor-ip-address activate neighbor
neighbor neighbor-ip-address send-community extended
Workaround: Reconfigure the address-family ipv4 mdt command in the BGP environment.
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Symptoms: A default route that is defined by the neighbor default-originate command may be ignored by the BGP neighbor.
Conditions: This symptom is observed on a Cisco router after a route flap in the network causes the default route to be relearned.
Workaround: Manually clear the BGP neighbor to enable the router to correctly relearn the default route.
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Symptoms: When there are link flaps in the network, various PE routers receive the following error message:
%BGP-3-INVALID_MPLS: Invalid MPLS label (1) received in update for prefix 155:14344:10.150.3.22/32 from 10.2.2.1Or, a local label is not programmed into the forwarding table for a sourced BGP VPNv4 network.
Conditions: These symptoms are observed when an iBGP path for a VPNv4 BGP network is present, and then a sourced path for the same route distinguisher (RD) and prefix is brought up.
Workaround: Remove the iBGP path. Note that when the sourced path comes up first, the symptoms do not occur.
Alternate Workaround: Use different RDs with the different PE routers. When the RD and prefix do not match exactly between the iBGP path and the sourced path, the symptoms do not occur.
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Symptoms: The MPLS labels for packets that are forwarded via CEF and MPLS over a BGP route may not match the labels in the BGP table, which may lead to traffic loss.
Conditions: This problem occurs under certain circumstances and timing conditions.
Workaround: When the symptom occurs, enter the clear ip route command for the prefix in the VRF.
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Symptoms: A Cisco 12000 series router that is running Cisco IOS Release 12.0(32)SY0f code may crash unexpectedly in a customer environment.
Workaround: There is no workaround.
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Symptoms: Virtual subinterfaces which result from PPP over ethernet sessions will not result in the required connected-routes to appear in the IP routing table. This causes connectivity failure for customer customers.
Workaround: Execute the clear ip route * command or targeted clear ip ro commands will cause the routes to appear, but this is not an acceptable workaround in the field.
Miscellaneous
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Symptoms: The ATM HA process may crash.
Conditions: This symptom is observed on a Cisco router that has VCS configured with local switching.
Workaround: There is no workaround.
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Symptoms: A router that is configured with ATM PVCs may generate the following type of error messages:
%COMMON_FIB-3-FIBIDBINCONS2: An internal software error occurred. Virtual- Access2.1 linked to wrong idb Virtual-Access2.1Conditions: This symptom is observed on a Cisco router that has virtual-template subinterfaces.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, enter the no virtual-template subinterface command, save the configuration to the startup configuration, and reload the router.
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Symptoms: The Cisco 10000 has its standby restarted by itself 5 minutes after booting.
Conditions: This symptom is observed when the system is in progress to standby cold-bulk. The high availability mode is SSO.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 does not display forwarding packets in Sampled Netflow. Only terminating packets are shown.
Conditions: With the show flow-sampler and show ip cache verbose flow commands, forwarding packets are not counted in these commands.
Workaround: There is no workaround.
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Symptoms: A Cisco 7200 series reloads unexpectedly when you enter the hw-module slot slot-number stop command for a T3 port adapter.
Conditions: This symptom is observed on a Cisco 7200 series that is configured with 100 EzVPN IVRFs on a DS3 interface of the T3 port adapter.
Workaround: There is no workaround.
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Symptoms: An Optical Services Module (OSM) may reset unexpectedly and generate the following error messages:
%POSLC-3-SOP: TxSOP-0 SOP. (source=0x18, halt_minor0=0x4000) %CWANLC-3-FATAL: Fatal Management interrupt, gen_mgmt_intr_status 0x0, line_mgmt_intr_status 0x1, reloadingConditions: This symptom is observed on a Cisco Catalyst 6500 series and Cisco 7600 series.
Workaround: There is no workaround.
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Symptoms: A memory leak may occur when tunnels or sessions are created and deleted in quick succession.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB, Release 12.2SRB, or Release 12.2SXH and that is configured for SNMP.
Workaround: If a virtual template is used, enter the no virtual-template snmp command to prevent the symptom from occurring. If no virtual template is used, there is no workaround.
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Symptoms: The CLI command show stacks on any router platform that uses IPC may show a process whose name appears to be corrupted, including a very large number of blank lines before the next line of the show stacks output is printed.
Conditions: The problem is seen when a show stacks is issued, or any other command that causes this to be executed (i.e., show tech-support, etc.). This is seen in router platforms that have IPC processes.
Workaround: There is no workaround.
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Symptoms: Router may crash if the sh ppp mul command is issued repeatedly.
Conditions: When the multilink status changes while the sh ppp mul command is issued.
Workaround: There is no workaround.
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Symptoms: After a forced switchover has occurred, ATM subinterfaces may not forward certain packets.
Conditions: This symptom is observed on a Cisco 7304 that has redundant NSE-100 route processors and that is configured for Reverse Path Forwarding (RPF). The symptom occurs only for ATM subinterfaces on which PVCs are configured.
Workaround: Disable RPF.
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Symptoms: Some CLI commands on any router platform that supports ISSU and uses IPC may show a.uses IPC may show a process whose name appears to be corrupted, including a very large number of blank lines before the next line of the place where the process name would be printed.
Conditions: This symptom is seen in router platforms that have ISSU related IPC process. The bug id CSCsh76558 fixed this issue for the show stacks command. This bug tracks a more generic fix.
Workaround: There is no workaround.
•
Symptoms: Channelized line cards may reload unexpectedly and an MR-APS failover occurs.
Conditions: These symptoms are observed on a Cisco 10000 series when packets with a source address of 127.xxx are being processed, causing a PXF crash that triggers a PRE switchover.
Workaround: Configure an access control list (ACL) to block packets with a source address of 127.xxx.
•
Symptoms: A Cisco 7304 PXF crashes every 10-60 minutes after upgrading from Cisco IOS Release 12.2(28)SB5 to Release 12.2(31)SB3.
Conditions: Issue detected on Cisco 7304 (NSE100) that is running Cisco IOS Release 12.2(31)SB2 or Release IOS 12.2(31)SB3. The crash occurs when these conditions are met:
–
–
Workaround: There is no workaround.
•
Symptoms: GLBP on a Cisco 7304 with 2xNPE-G100 remains stuck in Init after a switchover when SSO-GLBP is enabled (which is the default). The issue does not happen when "no glbp sso" is configured. The stuck in Init state can be cleared by a "shut/no shut" on the interface.
Conditions: This is seen on a Cisco 7304 with 2xNPE-G100.
Workaround: Disable SSO-GLBP with "no glbp sso" and glbp will run the reelection process upon SSO switchover.
•
Symptoms: CISCO ESR10008 implemented as a Broadband Remote Access Server (BRAS) for PPPoX customers will deplete all available IP address in any ip local IP address pool.
The show ip local pool pool_name command will report:
Inuse IP addresses and username but no actual Virtual Access interface associated..Inuse addresses:
10.8.7.196 username@cisco.com
10.8.7.197 username@cisco.com
10.8.7.198 username@cisco.com
10.8.7.199 username@cisco.com
10.8.7.200 username@cisco.com
10.8.7.202 Vi2.7545 usernaem@cisco.comConditions: This is observed with Cisco IOS Release 12.2(31)SB5.
The Customer Premise Equipment (CPE) requires several PPP handshakes (per 3-8sec time period) before finally establishing.
Virtual Router Forwarding (VRF) is assigned via a Radius Server.
Workaround:
1) Remove and reconfigure the ip local pool definition in the router global configuration.
2) Disable VRF assignment via Radius.
•
Symptoms: On Cisco 7304 platform, for ATM Card (PA-A3 and PA-A6) both vbr-rt and cbr cli is missing (not supported).
Workaround: There is no workaround.
•
Symptoms: Cef adjacency is going incomplete after the pcr on the pvp is changed on an ATM interface. CE router is getting 50% packet loss when pinging to remote CE. CE router pings the PE router no packet loss.
Conditions: Problem is found in Cisco IOS Release 12.2(31)SB5.
Trigger
Config t
interface ATM1/0
atm pvp 11 3000 << change
sh ip cef vrf Internet det | incl com
Adj source: IP adj out of ATM1/0.44604, addr x.x.x.x (incomplete)Workaround: Clear adjacency or shut/no shut on ATM interface
•
Symptoms: Cisco 10000 is caused to crash when ATM card installed (with or without traffic running through card) and card is Pulled.
Crash also occurs when hw-module slot reset command is issued.
Conditions: Crash occurs when using 1000+ multilink interfaces.
Workaround: Can avoid the problem by shutting down interfaces then the card before pulling. (Please Note: This does not always work)
•
Symptoms: A device with a PA-MC-2T3+ may reset because of a bus error if a channel group is removed while the show interface command is being used from another telnet session at the same time, and then the telnet session is cleared. The device may also display Spurious Memory Accesses.
Conditions: These symptoms have been observed in the latest Cisco IOS 12.4T and 12.2S releases.
Workaround: Do not remove a channel group while using the show interface command for that interface.
•
Symptoms: A Cisco 7500 router may crash in QoS code.
Conditions: ATM, serial interfaces have QoS configurations as output/input policy, and when peer is reloaded.
Workaround: There is no workaround.
•
Symptoms: When deleting a policy-map that is associated with 32,000 PPPoEoQinQ PTA sessions, the Cisco 10000 PRE3 experiences a bus error.
Conditions: The bus error is seen when using a Cisco 10000 PRE3 router as a PTA BRAS router for 32,000 PPPoEoQinQ sessions. All 32,000 sessions were attached to a single policy-map definition.
Workaround: Do not remove a widely used Policy-map from the configuration of a high scale BRAS router when the policy-map is attached to tens of thousands of PPPoEoQinQ sessions.
•
Symptoms: There is a memory leak and fragmentation in *Dead* process due to MallocLite. After disabling malloclite, it will be seen as memory allocated to the "Virtual Exec" process in the show memory allocating-process [total] command output.
Conditions: The leak occurs whenever the show vpdn session [l2tp] [all] username username command is used, and there are many non-matching entries. Memory will be leaked proportional to the number of non-matching usernames (approximately 170 bytes per non-match).
Workaround: Avoid using the show vpdn session [l2tp] [all] username username command.
•
Symptoms: An NSE-100 crashes after you have applied service policies to approximately 600 VLAN subinterfaces.
Conditions: This symptom is observed on a Cisco 7304 that has a very large configuration that causes memory exhaustion, for example, 4000 VLAN subinterfaces with nested policy maps that are applied to many of these subinterfaces.
Workaround: There is no workaround.
•
Symptoms: When configuring the command ATM PVP cellid cell rate, the cell rate automatically sets itself to the maximum.
When configuring the two commands below:
ATM PVP cellid cellrate
ATM PVP cellid no-f4-mgmt
The commands are entered individually, however when you view them using a show run, they seem to be merged into one command on one line as below:
ATM PVP cellid cellrate no-f4-mgmt
Then, when the router is reloaded, even though the configuration is saved, the command is erased as Cisco IOS does not recognize it as a valid command.
Workaround: There is no workaround.
•
Symptoms: In MLPoA, we are not able to add more than one member to the bundle.
Conditions: This problem is seen only when we have the ppp multilink group command configured in the VT.
Workaround: Configure the ppp multilink group command in the ATM interface
•
Symptoms: Traffic may fail after an aps manual/force cutover.
Conditions: This is observed when the router is booted up with configurations, not happening with configurations on the fly.
Workaround: There is no workaround.
•
Symptoms: Line card does not come up.
Conditions: This occurs when the hw-module subslot shutdown command is followed by the no card command and the no hw-module subslot shut command.
Workaround: Use the hw-module slot shutdown command on a full size card.
•
Symptoms: System may crash while applying QoS service-policy.
Conditions: When using a Cisco 10000 router with PRE3 RP board and Cisco IOS Release 12.2(31)SB, the system may crash when applying a QoS service-policy.
Workaround: There is no workaround.
Further Problem Description: The crash has not been seen in the field but was found to be possible in development.
•
Symptoms: After PRE3 failover, secondary PRE will continuously reboot.
Conditions: This occurs at this time, when an ESR-HH-1GE is installed and with minimal configuration.
Workaround: There is no workaround.
•
Symptoms: Multilink interfaces are down while running LFIoATM.
Conditions: The issue is seen with c10k2-p11-mz.122-31.4.13.SB8d.070928 image and not seen with c10k2-p11-mz.122-31.4.13.SB8b image.
Workaround: There is no workaround.
•
Symptoms: A router crashes on bootup due to column 3 memory exception.
Conditions: This symptom is observed on a Cisco 7304 NSE-100 Revision C (or EARLIER) that is running Cisco IOS Release 12.2(32)SR image built between 10/01/2007 and 10/16/2007.
Workaround: There is no workaround.
•
Symptoms: This is not an externally visible issue, there are no bugs/problems associated with this fix.
Conditions: There are no specific environment/runtime issues that are addressed by this fix.
Workaround: There is no workaround.
Further Problem Description: The code has been changed to use a componentized version of the cf-client-ids instead of the branch-specific monolithic version. This will prevent the IDs getting out of sync with the IDs in other branches/platforms/trains and ultimately prevent issues down the road. The two versions of the IDs (componentized vs monolithic) are identical and will not introduce any functionality change at this point.
•
Symptoms: A Cisco 10000 (PRE-2) that is running Cisco IOS Release 12.2(31)SB8 with a large (9mb) configuration fails to reach HOT state on the standby PRE due to a CPU hog by the BEM VERIFY process.
Conditions: This symptom is observed on a Cisco 10000 series router with redundant PREs configured for SSO and large configuration stored on flash disk.
Workaround: Disable the redundant PRE (for example, "hw-module pre b shutdown").
•
Symptoms: Outbound L2VPN traffic does not flow over GigabitEthernet interface on a Cisco 10000 router.
Conditions: PE router reload with bidirectional L2VPN and L3VPN traffic.
Workaround: Disable CDP on the router.
Wide-Area Networking
•
Symptoms: High CPU usage occurs on a Cisco 7301, and the following error message and traceback are generated:
%TCP-2-INVALIDTCPENCAPS: Invalid TCB encaps pointer:
0x0
-Process= "L2X SSS manager", ipl= 0, pid= 69
-Traceback= 0x606E43DC 0x60B9FAC8 0x60BA11C4 0x619F502C 0x619F4A2C
0x619F4D34 0x619F35C4 0x619F4FF4 0x619F6820 0x619F5ED8 0x619F6350 0x619CA1F4
0x619CA6C4 0x619D2524 0x619CABB4 0x619CAFA0Conditions: This symptom is observed on a Cisco 7301 that runs Cisco IOS Release 12.4(5b) with PPTP/VPDN connections after, on a connected platform, rate limiting is changed to MQC policy-based limiting of the bandwidth. Note that the symptom may be release-independent.
Workaround: There is no workaround.
•
Symptoms: The user is trying to add a map-class with fragmentation when interface level fragmentation is already configured.
Conditions:
1.
2.
Workaround: There is no workaround.
•
Symptoms: High CPU usage may occur when IPCP is being renegotiated. Eventually, the high CPU usage may cause buffers to be backed up, may cause error message to be generated, and may cause L2TP tunnels to be dropped.
Conditions: This symptom is observed on a Cisco router when clients renegotiate IPCP unnecessarily. You can verify this situation by enabling the debug ppp negotiation command or by configuring RADIUS authorization and then checking the virtual-access interface for the phrase "cloned from: AAA, AAA, ..." (that is, multiple instances of AAA) as identification.
Workaround: There is no workaround.
Further Problem Description: You can alleviate the situation somewhat by configuring the NCP Timeout to 15 seconds to disconnect clients that take a long time to renegotiate IPCP. You can also do the following:
–
–
–
–
Resolved Caveats—Cisco IOS Release 12.2(31)SB9
Cisco IOS Release 12.2(31)SB9 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB9 but may be open in previous Cisco IOS releases.
Basic System Services
•
This is the Cisco Product Security Incident Response Team (PSIRT) response to a vulnerability that was reported on the Cisco NSP mailing list on August 17, 2007 regarding the crash and reload of devices running Cisco IOS software images after executing a command that uses, either directly or indirectly, a regular expression. The original post is available at the following link:
http://puck.nether.net/pipermail/cisco-nsp/2007-August/043002.html
The Cisco PSIRT posted a preliminary response on the same day and is available at the following link:
http://puck.nether.net/pipermail/cisco-nsp/2007-August/043010.html
Preliminary research pointed to a previously known issue that was documented as Cisco bug ID CSCsb08386 (registered customers only), and entitled "PRP crash by show ip bgp regexp", which was already resolved. Further research indicates that the cur rent issue is a different but related vulnerability.
There are no workarounds available for this vulnerability. Cisco will update this document in the event of any changes.
The full text of this response is available at http://www.cisco.com/warp/public/707/cisco-sr-20070912-regexp.shtml.
IP Routing Protocols
•
Symptoms: With some VPN configurations such as configurations with a multipath import or an import map, the CPU usage of the router may be very high for a long time, even after BGP convergence has occurred.
Conditions: This symptom is observed on a Cisco router that functions in a highly scaled environment involving several hundred of VRFs and occurs after the router has been reloaded or after a switchover has occurred.
Workaround: There is no workaround.
Open Caveats—Cisco IOS Release 12.2(31)SB8
Cisco IOS Release 12.2(31)SB8 is a rebuild release for Cisco IOS Release 12.2(31)SB2. This section describes caveats that are open in Cisco IOS Release 12.2(31)SB8. There are other open caveats in Cisco IOS Release 12.2(31)SB8. However, open caveats are normally listed only for maintenance releases, and the listing of these caveats is an exception.
Interfaces and Bridging
•
Symptoms: A Cisco 7200 series that is configured for ATM and QoS may crash.
Conditions: This symptom is observed when you attempt to change the priority parameters while traffic is being processed.
Workaround: There is no workaround.
Miscellaneous
•
Symptoms: A router crashes when you unconfigure and then reconfigure MLPoFR.
Conditions: This symptom is observed on a Cisco router that has a QoS service policy with traffic shaping.
Workaround: There is no workaround.
•
Symptoms: After a forced switchover has occurred, ATM subinterfaces may not forward certain packets.
Conditions: This symptom is observed on a Cisco 7304 that has redundant NSE-100 route processors and that is configured for Reverse Path Forwarding (RPF). The symptom occurs only for ATM subinterfaces on which PVCs are configured.
Workaround: Disable RPF.
•
Symptoms: A Cisco 7200 series may crash when you perform a soft OIR of a port adapter.
Conditions: This symptom is observed when Frame Relay encapsulation is configured along with QoS on a PA-4T+ port adapter. However, the symptom is not specific to the PA-4T+ port adapter.
Workaround: There is no workaround.
•
Symptoms: When L2 local switching is configured for ATM-to-Ethernet interworking, there may be no connectivity between CE routers even though the L2 VCs are up.
Conditions: This symptom is observed on a Cisco 7304 only after you have disable and re-enabled the connect command for the ATM-to-Ethernet interworking configuration.
Workaround: Disable the PXF engine. If this is not an option, there is no workaround.
•
Symptoms: When one of the member links of a a Fast Etherchannel goes down while the other link remains active, a temporary drop in traffic that passes through the Fast Etherchannel may occur.
Conditions: This symptom is observed on a Cisco router that is configured for ARP and occurs only for large packets. The symptom does not occur with regular-sized packets such as 100-byte packets.
Workaround: Enter the clear arp command.
•
Cisco IOS contains multiple vulnerabilities in the Data-link Switching (DLSw) feature that may result in a reload or memory leaks when processing specially crafted UDP or IP Protocol 91 packets.
Cisco has released free software updates that address these vulnerabilities. Workarounds are available to mitigate the effects of these vulnerabilities.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080326-dlsw.shtml
Resolved Caveats—Cisco IOS Release 12.2(31)SB8
Cisco IOS Release 12.2(31)SB8 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB8 but may be open in previous Cisco IOS releases.
Basic System Services
•
Symptoms: RADIUS server authentication may not function for dialup and PPP clients.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.4(7) and that has the radius-server retry method round-robin command enabled. The symptom is not release-specific.
Workaround: Disable the radius-server retry method round-robin command. Note that the symptom does not occur in Release 12.3 or Release 12.3T.
•
Symptoms: A router crashes when you enter the show ip bgp regexp command.
Conditions: This symptom is observed on a Cisco router when BGP is being updated.
Workaround: Enable the new deterministic regular expression engine by entering the bgp regexp deterministic command and then enter the show ip regexp command. Note that enabling the new deterministic regular expression engine may impact the performance speed of the router.
•
Symptoms: When the initiator radius-proxy command is enabled on an ISG, extra characters are shown with the identifier in the output of show sss session and show radius-proxy client session commands.
Conditions: This symptom is observed on a Cisco router that functions as an ISG when the user name has at least 8 characters.
Workaround: Use a user name with less than 8 characters.
•
Symptoms: An LNS that has sampled NetFlow enabled may crash.
Conditions: This symptom is observed on a Cisco 7200 series that functions as an LNS.
Workaround: Disable sampled NetFlow. If this is not an option, there is no workaround.
EXEC and Configuration Parser
•
Symptoms: A router may unexpectedly reload with a bus error when you enter a command while the command buffer is full of white space.
Conditions: This symptom is observed when you enter a partial command and when the tab key is used while the command buffer is full.
Workaround: There is no workaround.
IP Routing Protocols
•
Symptoms: When the access control list (ACL) associated with a multicast boundary is modified to permit a statically joined group that has previously been denied by the boundary, the change does not take effect and the group continues to be blocked.
This issue also affects the static group memberships underlying MVPN tunnels, disrupting connectivity across them.
Conditions: This symptom is observed on a Cisco 12000 series that runs Cisco IOS Release 12.0(28)S4 or Release 12.0(32)S but appears to be platform- and release-independent.
Workaround: Disable and re-enter the ip multicast boundary command.
Alternate Workaround: Enter the clear ip mroute * command.
•
Symptoms: Networks do not show in the Multiprotocol BGP (MBGP) table, as can be seen in the output of the show ip mbgp command.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB, Release 12.2SR, Release 12.4, or Release 12.4T.
Workaround: Enter the clear ip bgp neighbor-address command to enable the networks to enter the MBGP table.
•
Symptoms: A Route Reflector (RR) does not withdraw a prefix that redistributes itself even if this prefix is removed from the BGP table.
Conditions: This symptom is observed on a Cisco router that functions as an RR that advertises two of the same prefixes with different Route Distinguishers (RDs) when one of these prefixes redistributes itself and when the other prefix is a route that is learned from an RR client via iBGP.
Workaround: There is no workaround.
ISO CLNS
•
Symptoms: IS-IS protocol packets may not be classified as high-priority. When this situation occurs during stress conditions and when the IS-IS protocol packets are mixed with other packets, the IS-IS protocol packets may be dropped because of their low-priority.
Conditions: This symptom is observed on a Cisco platform that is configured for Selective Packet Discard (SPD).
Workaround: Ensure that DSCP rewrite is enabled and then enter the following command:
mls qos protocol isis precedence 6
•
Symptoms: An IS-IS adjacency may flap when an RP switchover occurs.
Conditions: This symptom is observed on a Cisco router that is configured for IS-IS Multi-Topology, IS-IS NSF Awareness, and IPv4 and IPv6 unicast.
Workaround: There is no workaround.
•
Symptoms: IS-IS may not advertise the prefix of a passive interface to the IS-IS database on a local router.
Conditions: This symptom is observed on a Cisco router when you shut down an interface (for example, G9/1/1) of a 5-port GE SPA (SPA-5X1GE) that is installed in a SIP-600, replace the SPA-5X1GE with another card, and then enter the no shutdown interface configuration command on the interface at the same location (G9/1/1) on the new card. In this situation, the prefix for the interface (G9/1/1) is not advertised.
Possible Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the affected interface.
•
Symptoms: The prefix of a serial interface that is configured for PPP or HDLC and that functions as a passive interface for IS-IS may not be installed in the local IS-IS database.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(18)SXF6 but is not release-specific.
Workaround: Remove and reconfigure the passive-interface command.
First Alternate Workaround: Enter the clear isis * command.
Second Alternate Workaround: Enter any command that triggers the generation of the local IS-IS database.
Miscellaneous
•
Symptoms: A router that is configured for LAN Emulation (LANE) may reload because of a bus error, and the following error message may appear:
System returned to ROM by bus error at PC 0xXXXXXXXXConditions: This symptom is observed on a Cisco router only when the creation of switched virtual circuits (SVCs) fails.
Workaround: There is no workaround.
•
Symptoms: When Multilink PPP (MLP) is configured to use a virtual access interface as the bundle interface and when you apply a service policy with bandwidth guarantees that are higher than the bandwidth guarantees of the virtual access interface, an error message is generated because the service policy is not rejected nor enters the suspended mode.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB and that is configured for MLP and QoS.
Workaround: Add more links to the bundle interface and clear the virtual access interface.
•
Symptoms: The MPLS forwarding table is not shown on a router, causing packet drops in end-to-end connectivity across the MPLS cloud.
Conditions: This symptom is observed on a Cisco router that functions as a PE router after a switchover has occurred.
Workaround: There is no workaround.
•
Symptoms: Traffic may stop on a GRE tunnel that is configured on a VRF-enabled interface.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a PE router after a PRE-3 switchover has occurred.
Workaround: Reload the PXF engine.
Alternate Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the tunnel interface.
•
Symptoms: A router may crash when you configure an ATM PVC on an ATM point-to-point subinterface.
Conditions: This symptom is observed on a Cisco router when the ATM point-to-point subinterface is already part of a bundle.
Workaround: Configure the ATM PVC on an ATM multipoint subinterface.
•
Symptoms: An IP address that is configured for an IMA bundle on a PA-A3-8T1IMA port adapter may become lost after an online insertion and removal (OIR) of the port adapter.
Conditions: This symptom is observed on a Cisco 7304 when a PVC is configured on the IMA main interface on the PA-A3-8T1IMA port adapter and when there is continuous traffic.
Workaround: There is no workaround.
•
Symptoms: The xconnect ip address vcid pw-class class-name command may not be nvgened when it is entered along with the backup peer ip address vcid pw-class class-name command, and the parser submode "cfg-if-atm-l2trans-pvc-xconn" may not be entered.
Conditions: This symptom is observed on a Cisco 7304 that has an ATM interface when the encapsulation on the L2transport VC is ATM adaptation layer 0 (AAL0).
Workaround: There is no workaround.
•
Symptoms: A router that is configured for Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) may crash when LDP is configured globally or on an interface.
Conditions: This symptom is observed when you enter the show mpls ldp neighbor command while LDP sessions are coming up or going down.
Workaround: There is no workaround.
•
Symptoms: A Cisco router may crash because of a watch dog timeout while running the RIP routing protocol.
Conditions: This symptom is observed on a router that runs Cisco IOS Release 12.3(19) when an interface changes state at the exact same time that a RIP route that was learned on this interface is being replaced with a better metric redistributed route. For example, when RIP has learned the 192.168.1.0 network from Fast Ethernet 1/0 interface and then RIP learns the 192.168.1.0 network from a redistributed protocol that has a better metric, the RIP route is removed. However, when during this time the Fast Ethernet 1/0 interface goes down, the router may crash because of a watch dog timeout. Note that the symptom may also affect other releases.
Workaround: There is no workaround.
•
Symptoms: When PPPoE Relay is configured, only one session comes up successfully. All successive sessions fail. The initiation of more sessions brings down the existing sessions. If there are active sessions that are already existing (not necessarily PPPoE Relay sessions), the initiation of new PPPoE Relay sessions tears down all the sessions.
Conditions: These symptoms are observed on a Cisco router that functions in a Virtual Private Dialup Network (VPDN). The symptom occurs only for PPPoE Relay sessions and not for normal sessions.
Workaround: There is no workaround.
•
Symptoms: When packets that traverse an IP session are punted to the RP, the RP may read an incorrect MAC address.
Conditions: This symptom is observed on a Cisco 10000 series when the forwarding adjacency is not resolved for packets that traverse the IP session.
Workaround: There is no workaround.
•
Symptoms: Gigabit Ethernet output counters may become corrupted. When a QoS output policy map is applied while sessions are already up, the counters may show a value that resembles 2^32.
Conditions: This symptom is observed on a Cisco 10000 series only when the QoS output policy map is used for PPPoEoQinQ sessions and is applied after the router is booted and configured.
Workaround: Enter the clear counters command to reset the corrupted interface counters.
•
Symptoms: A CPUHOG condition may occur when an LDP session goes down.
Conditions: This symptom is observed on a Cisco router that is configured for MPLS LDP, that has more than 30 LDP sessions with peers, and that exchanges more than 5000 label bindings for each LDP session. The symptom occurs when the LDP session goes down shortly after it came up.
Workaround: There is no workaround.
•
Symptoms: For a Gigabit Ethernet interface, the ifOutNUcastPkts may decrement rather than increment.
Conditions: This symptom is observed on a Cisco 7304 that runs Cisco IOS Release 12.2(28)SB but could also occur in Release 12.2S.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series that is configured for QoS may crash.
Conditions: This symptom is observed when you remove a policy map from an ATM interface.
Workaround: There is no workaround.
•
Symptoms: The total free count on the secondary policy data index cannot be released after all sessions have been removed. This situation causes memory depletion. After memory has run out for the total free count on the secondary policy data index, tracebacks and error messages such as "The iEdge Toaster Client has been corrupted" and "The iEdge Toaster Client failed to allocate RP Memory" are generated.
Conditions: This symptom is observed on a Cisco 10000 series only when sessions are constantly brought up and torn down. When the sessions come up and remain up, the indexes are freed when you remove the sessions.
Workaround: There is no workaround.
•
This caveat consists of two symptoms, two conditions, and two workarounds:
1.
Condition 1: This symptom is observed on a Cisco 7200 series with an NPE-G2 that runs Cisco IOS Release 12.2(31)SB5 but is not release-specific.
Workaround 1: If HSRP is configured, enter the standby use-bia command. You may need enter the shutdown command followed by the no shutdown command to change the controller state.
2.
Condition 2: This symptom is observed on a Cisco 7200 series with an NPE-G2 that runs Cisco IOS Release 12.2(31)SB5 but is not release-specific.
Workaround 2: Configure a static MAC address.
•
Symptoms: Frame Relay service policy counters may not be updated.
Conditions: This symptom is observed on a Cisco 7304 when that has a POS interface that is configured for Frame Relay with a single DLCI that uses an output service policy. The symptom occurs after the following sequence of events:
1.
Current configuration: 143 bytes
!
interface POS5/0
no ip address
encapsulation frame-relay
load-interval 30
clock source internal
frame-relay intf-type dce
end
mft-73b#sh run int pos5/0.1
Building configuration...
Current configuration : 182 bytes
!
interface POS5/0.1 point-to-point
ip address 2.2.2.1 255.0.0.0
snmp trap link-status
frame-relay interface-dlci 1007
service-policy input in
service-policy output out2.
3.
mft-73b#Config t
mft-73b(confgi)# No int POS5/0.1 point-to-point4.
interface POS5/0
ip address 2.2.2.1 255.0.0.0
encapsulation frame-relay
load-interval 30
clock source internal
frame-relay interface-dlci 1007
frame-relay intf-type dce
service-policy input in
service-policy output out5.
6.
In this situation, the output of the command shows zero for the Frame Relay service policy counters.
Workaround: There is no workaround.
•
Symptoms: All E1 interfaces on a PA-MC-E3 port adapter may flap continuously even after the traffic has been stopped.
Conditions: This symptom is observed on a Cisco Catalyst 6500 series switch and Cisco 7600 series router that has a PA-MC-E3 port adapter when you configure 16 or 128 channel groups on each time slot (that is, time slots 1-31) and then generate traffic just above line rate traffic through all the channel groups. Note that the symptom is not platform-specific.
Workaround: Stop the traffic and reset the E3 controller of the PA-MC-E3 port adapter.
•
Symptoms: ISG may send the physical MAC address in ARP reply packets when Gateway Load Balancing Protocol (GLBP) may require the virtual MAC address (VMAC) for proper operation.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB, that functions as an ISG, and that connects to another ISG via an interface that is configured for GLBP.
Workaround: There is no workaround.
•
Symptoms: When you add a child policy to a VLAN shaper policy on a subinterface while sessions are active, memory may become corrupted or the router may crash.
Conditions: This symptom is observed on a Cisco 10000 series when the following sequence of events occurs:
1.
2.
3.
Workaround: There is no workaround.
Further Problem Description: In Cisco IOS Release 12.2(31)SB, the router does not crash but memory does become corrupted.
•
Symptoms: The ifOperStatus object for a 6-port channelized T3 line card may show that the T1 layer is up while the T3 controller is down. After the T3 controller is shut down, the ifOperStatus object for the controller should show that the T1 layer is down.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for SNMP when the T3 controller of the line card is configured with two T1 links and then shut down.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series that functions as an ISG may reload unexpectedly.
Conditions: This symptom is observed when the router has 16,000 user connections and when the memory pool is not able to allocate the memory even though memory is available.
Workaround: There is no workaround.
•
Symptoms: The ip flow-aggregation cache exp-bgp-prefix command may not show as a supported command because it is hidden.
Conditions: This symptom is observed on a Cisco 7304 router that has an NSE-100 or an NSE-150 and that runs Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround. However, the command is present in the Cisco IOS software image and is accepted when you enter it.
•
Symptoms: A PRE-3 may crash when you enter the show pxf cpu iedge policy detail command.
Conditions: This symptom is observed on a Cisco 10000 series while PPPoE over L2TP sessions are coming up.
Workaround: There is no workaround.
•
Symptoms: A memory leak at the SSM connection manager may occur when there are continuous Change of Authorization (CoA) transactions on PPPoE over L2TP sessions. When this situation occurs, the process memory continues to decrease, eventually an "AAA-3_LOW_MEM" error message is generated, and then incoming CoA packets are dropped. The output of the show aaa memory command displays the number of dropped CoA packets.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG.
Workaround: There is no workaround.
Further Problem Description: When there are no continuous CoA transactions on the PPPoE over L2TP sessions, the memory lead does not occur.
•
Symptoms: The input rate on Gigabit Ethernet interfaces shows fluctuating values even when the traffic is constant.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
•
Symptoms: A router may crash because of a bus error when you perform an OIR of a PA-MC-8TE1+ port adapter or when you enter the hw-module slot slot-number stop command for the slot in which the PA-MC-8TE1+ port adapter is installed.
Conditions: This symptom is observed on a Cisco 7200 series.
Workaround: There is no workaround.
•
Symptoms: Local switching through the PXF engine may not function, preventing local switching circuits from establishing connectivity.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 or NSE-150.
Workaround: There is no workaround.
•
Symptoms: The PXF engine may crash when you tear down a tunnel in an LNS multihop configuration.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an LNS multihop node when you enter the clear vpdn tunnel l2tp all on either the LAC or the terminating LNS.
Workaround: There is no workaround.
•
Symptoms: An ISG does maintain the subscriber traffic below the limit that is configured in the "Cisco: Service-Info" of the service profile but the accounting updates report the traffic counters without taking the rate limit into account.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG and occurs only when policing is enabled and traffic counters are configured. For other services such as prepaid services, the symptom does not occur.
Workaround: There is no workaround.
•
Symptoms: The PXF engine on a Cisco 10000 series may crash. When this situation occurs, the following error message is generated:
PXF DMA Error - Small Packet Handle Creating a Large Descriptor^MConditions: This symptom is observed on a Cisco 10000 series that functions as a LAC and that has QoS configured when the LNS sends a packet with an inner L2TP packet that is padded to a large number of bytes such that the L2TP packet is much larger than the payload.
Workaround: Disable QoS on the LAC in the downstream direction.
TCP/IP Host-Mode Services
•
Symptoms: When you enter the copy ftp disk command, the copy operation may fail and cannot be terminated, further copy commands may fail, and a TCP vty session for the purpose of troubleshooting the situation may fail and cannot be terminated.
Conditions: These symptoms are observed on a Cisco platform when the FIN flag is set in the initial ESTAB message from a neighbor. You must reload the router to recover from the symptoms.
Workaround: Do not enter the copy ftp disk command. Rather, enter the copy tftp disk command.
Wide-Area Networking
•
Symptoms: The standby processor on a router that is configured for PPP may reload unexpectedly.
Conditions: This symptom is observed on a Cisco router when the debug ppp redundancy command is enabled on the standby processor.
Workaround: Do not enable the debug ppp redundancy command on the standby processor.
•
Symptoms: When you delete a Frame Relay subinterface, the following error message and a traceback may be generated continuously:
SYS-2-BADSHARE: Bad refcount in retparticleConditions: This symptom is observed on a Cisco router when a Frame Relay subinterface with a service policy is applied inside a VRF.
Workaround: Recreate and then delete the interface. When you do so, the error message and a traceback are no longer generated.
•
Symptoms: The traffic flow stops and tracebacks are generated when the fragmentation size is changed by using an MQC shaped policy on a PVC. When the fragmentation size is set to a value equal to or larger than 700, the router hangs.
Conditions: This symptom is observed on a Cisco 7206VXR that runs Cisco IOS Release 12.2(31)SB4.
Workaround: When the symptom has occurred, you must power-cycle the router. To prevent the symptom from occurring, first remove fragmentation, change the size, and then re-apply the map class. To prevent the router from hanging, use FRTS.
•
Symptoms: A PRE-3 may crash at the "pppatm_pas_fs" function.
Conditions: This symptom is observed on a Cisco 10000 series that runs the c10k3-p11-mz image of Cisco IOS Release 12.2(31)SB1 and that is configured for PPP. The symptom occurs after a write operation. The symptom may not be platform-specific.
Workaround: There is no workaround.
•
Symptoms: After a SSO switchover has occurred, a peer router cannot ping the IP address of an MFR interface that is up.
Conditions: This symptom is observed inconsistently on a Cisco 10000 series only when a MFR interface is created newly and only after the first SSO switchover has occurred.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the affected MFR interface. Once you have done so, you still can ping the interface after subsequent SSO switchovers have occurred.
•
Symptoms: The ppp mtu pppoe unlimited enhancement command may not function correctly.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB7
Cisco IOS Release 12.2(31)SB7 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB7 but may be open in previous Cisco IOS releases.
Interfaces and Bridging
•
Symptoms: A PVC that is shut down by OAM may continue to receive and forward traffic. This situation causes problems in an APS 1+1 redundancy configuration in which the standby router has a PVC that is shut down by OAM but continues to receive all traffic.
Conditions: This symptom is observed on a Cisco router that has an ATM port adapter.
Workaround: In an IPv4 configuration, shut down the subinterface manually or enter the ip verify unicast reverse-path command. In an MPLS configuration, shut down the subinterface manually.
IP Routing Protocols
•
Symptoms: A router may delete the VPNv4 prefixes from the BGP table, even though the counters in the output of the show ip bgp command may indicate that the VPNv4 prefixes are present in the BGP table. This situation may cause loss of VPN connectivity.
Conditions: This symptom is observed on a Cisco router that is configured for MPLS VPN and that functions as a PE router.
Workaround: There is no workaround. When the symptom occurs, enter the clear ip bgp * command to restore proper operation of the router.
•
Symptoms: A router may reload unexpectedly when a routing event causes multicast boundary to be configured on a Reverse Path Forwarding (RPF) interface.
Conditions: This symptom is observed on a Cisco platforms that is configured for PIM.
Workaround: Remove multicast boundary from the configuration.
•
Symptoms: The following error message may be generated on a router that is configured for VPN or VPNv4:
For VPN:
ALIGN-3-SPURIOUS: Spurious memory access made at bgp_vpn_afmodify_walkFor VPNv4:
ALIGN-3-SPURIOUS: Spurious memory access made at bgp_vpnv4_afmodify_walkConditions: This symptom is observed on a Cisco router that is configured for BGP and IPv4 in a VRF address-family configuration and that imports routes from a VRF.
Workaround: There is no workaround. However, the error message is of a cosmetic nature and can be ignored.
Miscellaneous
•
Symptoms: A PA-CC in which a PA-A6 port adapter is installed may crash continuously, preventing the PA-A6 from coming up.
Conditions: This symptom is observed on a Cisco 7304 after you have entered the no shutdown command on an interface of the PA-A6 port adapter.
Workaround: There is no workaround.
•
Symptoms: For PPPoEoE sessions on a Cisco 10000 series, the output of the show interface virtual-access command shows numbers for received packets and bytes that are double the actual numbers.
Conditions: This symptom is observed only for PPPoEoE packets that are punted to the Route Processor (RP).
Workaround: There is no workaround.
Further Problem Description: The symptom occurs because the packet count is incremented for both the PXF engine and the RP.
•
Symptoms: Input statistics for a serial interface that is part of an MLP bundle that is configured for LFI may be inaccurate (that is, the statistics may be too high).
Conditions: This symptom is observed on a Cisco 10000 series after the shutdown interface configuration command followed by the no shutdown interface configuration command is entered on the multilink interface at the far end. The symptom occurs because the "seq_num" is not reset to zero after the multilink interface at the far end is shut down and brought up again.
Workaround: There is no workaround.
•
Symptoms: When you paste a large configuration for a channelized port adapter, the standby RP may crash.
Conditions: This symptom is observed on a Cisco 7304 that is configured for HA.
Workaround: Copy the configuration for the channelized port adapter to the startup configuration and then reload the router.
Alternate Workaround: Do not copy the configuration. Rather, enter the configuration manually.
•
Symptoms: The PXF engine may crash, and the following error message may be generated:
C10KEVENTMGR-1-MAJOR_FAULT PXF DMA TBB Length ErrorConditions: This symptom is observed on a Cisco 10000 series sometime after you have changed the FRF.12 configuration.
Workaround: The following procedures reduce the likelihood of the symptom occurring:
1.
2.
For example, consider the following configuration:
class-map match-any dscp_EF
match ip dscp ef
class-map match-any dscp_EF_ipprec_5
match ip dscp cs5 ef
class-map match-any dscp_AF4x
match ip dscp cs4 af41 af42 af43
class-map match-any dscp_AF3x
match ip dscp cs3 af31 af32 af33
!
policy-map FRFRAG_child_A
class dscp_EF
priority
police percent 50 25 ms 0 ms conform-action transmit exceed-action
transmit violate-action
drop
class dscp_AF4x
bandwidth percent 30
random-detect dscp-based
random-detect dscp 32 11 33 1
random-detect dscp 34 11 33 1
random-detect dscp 36 4 11 1
random-detect dscp 38 4 11 1
class dscp_AF3x
bandwidth remaining percent 16
random-detect dscp-based
random-detect dscp 18 11 33 1
random-detect dscp 20 4 11 1
random-detect dscp 22 4 11 1
random-detect 11 33 1
class class-default
bandwidth remaining percent 4
random-detect dscp-based
!
policy-map FRFRAG_A
class class-default
shape 128
service-policy FRFRAG_child_A
!
map-class frame-relay FRFRAG
no frame-relay adaptive-shaping
service-policy output FRFRAG_A
frame-relay fragment 80To modify this configuration, start by defining a new policy with the intended result:
#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
(config)# policy-map FRFRAG_child_B
(config-pmap)# class dscp_EF_ipprec_5
(config-pmap-c)# priority
(config-pmap-c)#police percent 50 25 ms 0 ms conform-action transmit
exceed-action transmit
violate-action drop
(config-pmap-c)# class dscp_AF4x
(config-pmap-c)# bandwidth percent 30
(config-pmap-c)# random-detect dscp-based
(config-pmap-c)# random-detect dscp 32 16 40 1
(config-pmap-c)# random-detect dscp 34 16 40 1
(config-pmap-c)# random-detect dscp 36 6 16 1
(config-pmap-c)# random-detect dscp 38 6 16 1
(config-pmap-c)# class dscp_AF3x
(config-pmap-c)# bandwidth remaining percent 16
(config-pmap-c)# random-detect dscp-based
(config-pmap-c)# random-detect dscp 18 16 40 1
(config-pmap-c)# random-detect dscp 20 6 16 1
(config-pmap-c)# random-detect dscp 22 6 16 1
(config-pmap-c)# random-detect 16 40 1
(config-pmap-c)# class class-default
(config-pmap-c)# bandwidth remaining percent 4
(config-pmap-c)# random-detect dscp-based
(config-pmap-c)#
(config-pmap-c)# policy-map FRFRAG_B
(config-pmap)# class class-default
(config-pmap-c)# shape 256
(config-pmap-c)# service-policy FRFRAG_child_B
(config-pmap-c)# exit
(config-pmap)# exit
(config)#Then, remove the fragment keyword from the map class:
(config)# map-class frame-relay FRFRAG
(config-map-class)# no frame-relay fragment 80
(config-map-class)# endTo allow time for the RP to process the configuration change, wait approximately 2 minutes. Then, remove the old service policy and apply the new one:
#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
(config)# map-class frame-relay FRFRAG
(config-map-class)# no service-policy output FRFRAG_A
(config-map-class)# service-policy output FRFRAG_B
(config-map-class)# endWait approximately 2 minutes, and then re-apply the fragment keyword to the map class:
#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
(config)# map-class frame-relay FRFRAG
(config-map-class)# frame-relay fragment 80
(config-map-class)# endFurther Problem Description: Note that caveat CSCeh48541 is not related to this caveat because there are no "Priority Pak Q" drops on the interfaces.
•
Symptoms: When the service local command is configured under a policy map, service is denied.
Conditions: This symptom is observed on a Cisco router that functions as an ISG and that is configured for AAA.
Workaround: There is no workaround.
•
Symptoms: A compact flash card in a router may not be accessible from the Cisco IOS prompt or from the ROMmon prompt. When you attempt to access the flash card from the Cisco IOS prompt, the following error message is generated:
%Error opening disk0:/ (No device available)From the ROMmon prompt, any attempt to access the compact flash card to boot the image fails.
Conditions: This symptom is observed on a Cisco 7304 that has a compact flash card from a particular this-party vendor. The compact flash card has a date code is earlier than "060728" (that is, 7/28/06) and a vendor part number that starts with "CCF".
Workaround: There is no workaround.
•
Symptoms: After a switchover occurs on a Cisco 10000 series, the boot variable may not be present on the standby PRE, which can be seen in the output of the show bootvar EXEC command.
Conditions: This symptom is observed when the following events occur:
1.
2.
3.
In this situation, when the new standby PRE comes up and after the bulk synchronization has occurred, the BOOT variable is not present. If another switchover occurs, the BOOT variable is not present on the new active PRE nor the new standby PRE.
Workaround: Ensure that the boot system global configuration command is present in the running configuration.
•
Symptoms: A Cisco 7304 with an NSE-150 may not be stable in a configuration with 1000 MVPNs and may crash after all protocols (BGP, OSPF, PIM and IGMP), have started.
Conditions: This symptom is observed when there is a large number of OSPF routes and occurs because the router runs out of I/O memory. OSPF uses I/O memory to allocate a database summary. Therefore, with a large umber of OSPF routes, more I/O memory is required.
Workaround: Increase the size of the I/O memory.
•
Symptoms: A Cisco 10000 series may generate the following error message:
%HQF_MAP_TT-3-HQF: hmt_get_new_class_blt_index error detected: Failed to allocate new class blt.Conditions: This symptom is observed on a Cisco 1000 series that has a PRE-3 after sessions that have queueing policy maps attached have been churned more than 1 million times.
Workaround: There is no workaround.
•
Symptoms: Poor throughput may occur when MLP and QoS are configured, and 10 percent of the traffic may be lost.
Conditions: This symptom is observed on a Cisco 10000 series when a priority queue is configured and when traffic is queued only in non-priority queues. The symptom occurs only with certain QoS policies and packet sizes.
Workaround: There is no workaround. Note that the symptom is unlikely to occur in a production network.
•
Symptoms: After an interface has flapped, packets may be dropped, and a "FIB RPF fail" error message may be generated for the PXF engine. This situation affects asymmetric routing.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Configure Reverse Path Forwarding (RPF) on the interface and then remove it again, as in the following example. Doing so restores the original interface flags on the PXF engine.
int atm 1/0/0.100
ip unicast reverse-path
no ip unicast reverse-path•
Symptoms: A Cisco 7304 may hang and may not generate any keepalives or route updates.
Conditions: This symptom is observed only on a Cisco 7304 that has an NSE-150.
Workaround: Call Cisco TAC for assistance with a workaround.
Further Problem Description: The root cause of the symptom is a lock-up in the transmission of packets from the RP to the PXF engine. The packets are not completely read from an internal memory. This situation eventually blocks the transmission of later packets from the RP to the PXF engine.
•
Symptoms: After a PRE switchover has occurred, a PVC may hang. When the oam-pvc manage command is configured, the PVC in the down state; when the oam-pvc manage command is not configured, the PVC appears to be up but no traffic passes through the PVC.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for SSO.
Workaround: Delete and re-define the PVC to recover from the symptoms.
•
Symptoms: A T3/E3 serial SPA may not come up because the line protocol remains down, and the output of the show controllers serial command does not generate any output for the T3/E3 serial SPA.
Conditions: This symptom is observed on a Cisco 7304 when you apply the configuration for the first time after the router has booted.
Workaround: Unconfigure and reconfigure the card type command for the T3/E3 serial SPA.
Wide-Area Networking
•
Symptoms: When you enter the shutdown interface configuration command followed by the no shutdown interface configuration command on an MFR interface when the bundle links are down, the serial interfaces that are associated with the MFR interface remain in the IDLE state.
Conditions: This symptom is observed on a Cisco router that is configure for MFR.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on each serial interface that is associated with the MFR interface.
•
Symptoms: When a a multilink bundle comes up, the following error message may be generated:
SYS-2-INTSCHED: `idle' at level 2 -Process= "PPP Events"Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB6
Cisco IOS Release 12.2(31)SB6 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB6 but may be open in previous Cisco IOS releases.
Basic System Services
•
Symptoms: The MIB object value of "Number of Octets in use" (rttMonCtrlOperOctetsInUse) is always set to zero.
Conditions: This symptom is observed on a Cisco router that has an Echo probe configured.
Workaround: There is no workaround.
•
Symptoms: A router may crash when you enter the show cdp entry device-name command.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G2 and a Port Adapter Jacket Card in which a PA-2CT3 port adapter is installed.
Workaround: There is no workaround.
•
Symptoms: The output of the show ip cache flow command for NetFlow on an LNS shows the physical ingress interface as the source interface for packet flows instead of the virtual-access interface.
Conditions: This symptom is observed on a Cisco 7206VXR that runs Cisco IOS Release 12.2(28)SB3 and that functions as an LNS when the following configuration is present:
–
–
Workaround: Do not enter the ip flow ingress command on the physical ingress interface. Rather, enter the ip flow ingress command on the virtual-template interface, bring down the tunnel, and then bring up the tunnel.
•
Symptoms: The attribute list may not be downloaded for a particular service.
Conditions: This symptom is observed on a Cisco platform that is configured for AAA when local authorization is configured and when the attribute list is downloaded. The following shows a configuration in which the symptom occurs:
policy-map type service abcd
aaa attribute list cisco
service localaaa attribute list cisco
attribute type addr-pool "cisco" protocol ip
attribute type ppp-author-list "cisco"
attribute type ppp-authen-list "cisco"Workaround: Ensure that the same name is used for the policy-map-name argument of the policy-map type service policy-map-name command (abcd in the example above) and the list-name argument of the aaa attribute list list-name command (cisco in the example above).
•
Symptoms: A Cisco router that functions as an ISG may not send RADIUS attribute 44 in the RADIUS Access Request when the vrf default keywords are present in the command line, as in the following example:
radius-server attribute 44 include-in-access-req vrf default
This situation affects the prepaid billing service for ISG-based customers because the billing system cannot re-authorize a subscriber after its quota runs out. The billing system is not able to consolidate the AAA accounting sessions without RADIUS attribute 44 in the RADIUS Access Request for re-authorization. Even if the ISG prepaid threshold is zero, re-authorization fails because the service quota is exhausted, but subscriber's session remains active.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB or one of its rebuilds because in these releases the vrf default keywords are added by default.
Workaround: There is no workaround.
IP Routing Protocols
•
Symptoms: The EIGRP Stub Routing feature may be missing from the configuration.
Conditions: This symptom is observed when a Cisco router on which the EIGRP Stub Routing feature is enabled is reloaded, or when the Enhanced Interior Gateway Routing Protocol (EIGRP) process is restarted.
Workaround: There is no workaround. Re-enable the EIGRP Stub Routing feature.
•
Symptoms: The CPU usage of the RP may be very high on a router that is configured for eiBGP Multipath Load Sharing.
Conditions: This symptom is observed on a Cisco router that advertises a few prefixes that are loadbalanced.
Workaround: There is no workaround.
•
Symptoms: A router crashes because of memory corruption when you bring up Gigabit Ethernet links and BGP neighbor adjacencies, and an error message is generated, indicating that a block overrun and rezone corruption have occurred.
Conditions: This symptom is observed on a Cisco Catalyst 6500 series and a Cisco 7600 series that are configured for BGP. However, the symptom is not platform-dependent.
Workaround: There is no workaround.
•
The Cisco Next Hop Resolution Protocol (NHRP) feature in Cisco IOS contains a vulnerability that can result in a restart of the device or possible remote code execution.
NHRP is a primary component of the Dynamic Multipoint Virtual Private Network (DMVPN) feature.
NHRP can operate in three ways: at the link layer (Layer 2), over Generic Routing Encapsulation (GRE) and multipoint GRE (mGRE) tunnels and directly on IP (IP protocol number 54). This vulnerability affects all three methods of operation.
NHRP is not enabled by default for Cisco IOS.
This vulnerability is addressed by Cisco bug IDs CSCin95836 for non-12.2 mainline releases and CSCsi23231 for 12.2 mainline releases.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20070808-nhrp.shtml.
•
Symptoms: Routes redistributed from other routing protocols to BGP will be deleted and re-added after an NSF switchover, potentially causing traffic to go down for a long period of time.
Conditions: This symptom may occur when the route is redistributed from other routing protocols (such as OSPF, ISIS, EIGRP) to BGP.
Workaround: There is no workaround.
•
Symptoms: The attributes that are configured in a site map may not automatically be applied to the BGP table when the associated interface is running other routing protocols such as RIP or OSPF.
Conditions: This symptom is observed on a Cisco router when routes are redistributed into BGP.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the associated interface.
•
Symptoms: On a PE router in an EIGRP network, EIGRP prefixes are redistributed into BGP but are missing their EIGRP-derived extended community values.
Conditions: This symptom is observed only when a network command is manually entered in "router EIGRP" mode while the redistribute eigrp command already exists in the BGP configuration. The symptom does not occur if all final configuration statements are present at router bootup time.
Workaround: Re-enter the redistribute eigrp command in the BGP configuration. There is no need to first remove the command because entering the command triggers a new redistribution event.
•
Symptoms: When the BGP session between a Route Reflector (RR) and PE router flaps, the RR may no longer send some routes to the PE router.
Conditions: This symptom is observed on a Cisco router that runs a Cisco IOS software image that integrates the fix for caveat CSCsi85222. A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsi85222. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, enter the clear ip bgp * all in command on the PE router to retrieve all routes from the RR.
Miscellaneous
•
Symptoms: A router may reload because of a memory corruption when you query via getmany or getbulk the entire ciscoCBQosMIB (1.3.6.1.4.1.9.9.166) or when you poll the cbQosQueueingStatsTable or cbQosPoliceStatsTable.
Conditions: This symptom is observed on a Cisco 7500 series that runs the rsp-jsv-mz image of Cisco IOS interim Release 12.3(11.4) when the following tables in the CBQOSMIB are polled:
–
–
–
–
The symptom may not be platform-specific nor release-specific.
Workaround: Do not query the entire ciscoCBQosMIB and do not poll the cbQosQueueingStatsTable or cbQosPoliceStatsTable.
•
Symptoms: A Cisco 10000 series that has a PRE-3 may reload unexpectedly when PPPoA calls are brought up aggressively.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2SB during a test in which sessions are brought up and down by emulating client power outages, forcing OIRs, and switchovers.
Workaround: There is no workaround.
•
Symptoms: A router that is configured for HA may unexpectedly reload because of a spurious memory access.
Conditions: This symptom is observed on a Cisco 10000 series when an L2TP tunnel interface flaps, causing a spurious memory access in the chunk memory. Note that the symptom is platform-independent.
Workaround: There is no workaround.
Further Problem Description: Note that SSO is not supported on a Cisco 10000 series that runs Cisco IOS Release 12.2(28)SB or one of its rebuilds and that is configured for broadband aggregation:
"In Cisco IOS Release 12.2(28)SB, the Cisco 10000 series supports Route Processor Redundancy Plus (RPR+), and Stateful Switchover (SSO). However for broadband aggregation features, the Cisco 10000 series supports RPR+ only."
For more information, see the Broadband Aggregation and Leased-Line Overview document:
http://www.cisco.com/en/US/products/hw/routers/ps133/
products_configuration_gu ide_chapter09186a00805057de.html•
Symptoms: After an SSO switchover has occurred, the standby supervisor may not come up because the startup configuration does not synchronize to the standby supervisor.
Conditions: This symptom is observed on a Cisco 7600 series that runs Cisco IOS Release 12.2(33)SRB after a single or multiple SSO switchovers have occurred. However, the symptom is not platform- nor release-specific.
Workaround: There is no workaround.
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Symptoms: Authentication may be skipped during account logon.
Conditions: This symptom is observed when an IP session is brought up with a default service before account logon.
Workaround: Do not configure a default service before account logon.
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This caveat consists of two symptoms, two conditions, and two workarounds:
1.
Condition 1: This symptom is observed on a Cisco 7200 series that is configured with an NPE-G2 and a PA-8B-ST port adapter. The symptom does not occur with an NPE-G1.
Workaround 1: Perform a software OIR to bring up the port adapter.
2.
Condition 2: This symptom is observed on a Cisco 7200 series that is configured with an NPE-G2 and a PA-8B-ST port adapter. The symptom does not occur with an NPE-G1.
Workaround 2: Enter the debug bri-interface command to bring up the ISDN layers.
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Symptoms: Shaping and random detect may not be enabled when you attempt to do so.
Conditions: This symptom is observed on the fourth native Gigabit Ethernet port on a Cisco 7201 that runs Cisco IOS Release 12.2SB but may not be platform- and release-specific.
Workaround: There is no workaround.
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Symptoms: A router may crash when you attach a VC class to an ATM bundle.
Conditions: This symptom is observed on a Cisco 7200 series but is platform-independent.
Workaround: There is no workaround.
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Symptoms: When an IMA group interface is configured on a Cisco 7600 series, the output of the show ip interface brief command may show the line protocol of member link as down when it is not down.
Conditions: This symptom is observed when the Cisco 7600 series has an IMA group interface configured on a PA-A3-8T1IMA or PA-A3-8E1IMA port adapter. The symptom is not platform-specific.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the member link of the IMA group on the PA-A3-8T1IMA or PA-A3-8E1IMA port adapter.
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Symptoms: When you attempt to create a new VRF, the following error message may be generated:
%FIB-SP-STDBY-4-FIBCBLK: Missing cef table for tableid 2 during route update XDR event SLOT 2:
%FIB-4-FIBCBLK: Missing cef table for tableid 2 during route update XDR event
%FIB-SP-4-FIBCBLK: Missing cef table for tableid 2 during route update XDR eventConditions: This symptom is observed on a Cisco 7600 series that runs Cisco IOS Release 12.2(33)SRA1 but may be platform- and release-independent.
Workaround: There is no workaround.
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Symptoms: Malformed SSL packets may cause a router to leak multiple memory blocks.
Conditions: This symptom is observed on a Cisco router that has the ip http secure server command enabled.
Workaround: Disable the ip http secure server command.
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Symptoms: When you perform and OIR of a SPA-2XOC3-POS, the HC counters may stop functioning.
Conditions: This symptom is observed on a Cisco 7304 that runs Cisco IOS Release 12.2(25)S10 or a later release or Release 12.2(28)SB5.
Workaround: Do not perform an OIR. Rather, reload the SPA when there is an opportunity.
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Symptoms: After you have reloaded a router, VRF routes disappear.
Conditions: This symptom is observed when you reload a router the processes a heavy traffic flow.
Workaround: Enter the clear ip route vrf vrf-name command.
Alternate Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface from which the VRF routes have disappeared.
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Symptoms: A software-forced reload may occur on a Cisco 7301.
Conditions: This symptom is observed on a Cisco 7301 that terminates several thousand broadband subscribers. Note that the symptom may be platform-independent.
Workaround: There is no workaround.
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Symptoms: Queue and buffer leaks may occur, and the output of the show pxf cpu queue summary command may show that many queues are being recycled.
Conditions: This symptom is observed on a Cisco 10000 series that has a class queue configured for a UDP port and occurs after a large number of serial interfaces flap on the router at the far-end.
Workaround: Add a queue-limit for the class queue on the UDP port, as in the following example:
policy-map IPBH
class udp_traffic
police percent 90 17 ms 17 ms conform-action transmit exceed-action drop
violate-action drop
priority
queue-limit 512
class tcp_traffic
bandwidth percent 9
queue-limit 256
class class-default
bandwidth percent 1
queue-limit 128•
Symptoms: IP SLA operations on a router that has a response time reporter (RTR) enabled may fail at the source. The UDP socket events are not received by the RTR responder process, and the UDP socket events are missing when a UDP packet is routed through a VRF.
Conditions: These symptoms are observed on a Cisco router that runs Cisco IOS Release 12.2SB. You can verify that the symptoms are occurring through any of the following commands:
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–
–
Workaround: Use IP SLA operations without VRFs.
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Symptoms: When L4 redirect is configured for a session or traffic class, the downstream packet counters may be double counted in the output of the show pxf cpu isg interface virtual access command.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG.
Workaround: There is no workaround.
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Symptoms: High PQ latency may occur with a large number of PPPoEoX sessions in a LAC/LNS topology when policy maps are applied to sessions either via a virtual template or via RADIUS AVPs.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3.
Workaround: There is no workaround.
Further Problem Description: The symptom does not occur for the same PPPoEoX QoS configuration in a PTA environment.
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Symptoms: When a VLAN group policy is attached to a Gigabit Ethernet main interface, queues are allocated properly on the interface. However, after you have entered the microcode reload pxf command, or after a PXF crash has occurred, the queues are no longer properly allocated.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround to prevent the symptom from occurring. After the symptom has occurred, remove and re-attach the VLAN group policy to the Gigabit Ethernet main interface.
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Symptoms: An NPE-G1 may crashes because of a bus error and generate the following error message:
%ALIGN-1-FATAL: Illegal access to a low address TLB (store) exception, CPU signal 10, PC = 0x61F1D0D0Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(31)SB2 and that is configured for L2TP. The symptom may not be platform-specific.
Workaround: There is no workaround.
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Symptoms: A router may crash when you remove a PBR configuration from a virtual access interface.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Do not configure PBR on an interface that is used for user sessions.
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Symptoms: Multilink interfaces stop transmitting traffic after a PRE failover has occurred.
Conditions: This symptom is observed on a Cisco 10000 series that has two OC-12 ports that function as active ports in an APS configuration and that are configured with multiple multilink interfaces.
Workaround: Enter the microcode reload pxf command. Note that entering the hw-module subslot slot/subslot reset command for the affected ports does not resolve the symptom.
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Symptoms: DNS requests from a PC client may time out.
Conditions: This symptom is observed on a cisco router that functions as an ISG, that is located between a PC and a DNS server, and that redirect DNS requests to a local DNS server.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series may show the wrong traffic class statistics for a session when traffic class services with priorities are applied dynamically to the session.
Conditions: This symptom is observed only when traffic class services are downloaded that have higher priorities than the priorities that are already loaded onto the session.
Workaround: There is no workaround.
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Symptoms: The output of the show policy-map interface command and show policy-map session command shows all policing counters as zero for policies that are applied to LNS sessions.
Conditions: This symptom is observed on a Cisco 10000 series and occurs only with LNS sessions. The symptom does not occur with LAC or PTA sessions.
Workaround: There is no workaround.
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Symptoms: There may be a delay in the creation of IP sessions over an interface that is configured for QinQ support.
Conditions: This symptom is observed on a Cisco router that functions as an ISG when the initiator dhcp class-aware command is enabled to place the clients in a specific VRF.
Workaround: There is no workaround.
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Symptoms: A memory leak may cause a slow response and time-outs during the set-up of new IP sessions, and the connection speed for established sessions may be very slow. To verify that there is a memory leak, enter the show memory debug leak summary command, and look for "Alloc PC" in the output.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB3 and that has the following configuration commands under a BVI or on an IP interface:
service-policy type control XXXX
ip subscriber routed
initiator dhcp class-awareWorkaround: There is no workaround.
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Symptoms: A router may run out of memory when you scale sessions with QoS and distribute them among a large number of subinterfaces.
Conditions: This symptom is observed on a Cisco router such as a Cisco 10000 series with a PRE3 that is configured for Hierarchal Queuing Framework (HQF). The symptom is not platform-specific. The symptom occurs when the following conditions are present:
–
–
–
–
Workaround: There is no workaround.
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Symptoms: The PXF engine of a Cisco 10000 series may crash and the following error message may be generated:
%C10KEVENTMGR-1-MAJOR_FAULT: PXF DMA FTC Move Command with Continue Error PXF DMA Error - Input Command Has Sequence Problem, Restarting PXF in an LNS config.Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 and that runs Cisco IOS Release 12.2(31)SB3b and that processes L2TP traffic.
Workaround: There is no workaround.
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Symptoms: A router may hang for approximately 7 minutes.
Conditions: This symptom is observed when you attempt to configure the range pvc command in a manner that exceeds the interface limit.
Workaround: There is no workaround.
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Symptoms: On a pseudowire that is configured on an OC-12 ATM interface, when you delete the oam-ac emulation-enable command, enter the write memory command, and then initiate an SSO switchover, the new standby PRE continues to reboot because of a configuration mismatch with the new active PRE.
Conditions: This symptom is observed on a Cisco 10000 series when the new active PRE has the oam-ac emulation-enable command in its configuration but the new standby PRE does not, causing a configuration mismatch. The symptom may not be platform-specific.
Workaround: Reload the new active PRE, then remove the oam-pvc manage 0 command from its configuration.
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Symptoms: A bus error crash is seen on a Cisco router that is running Cisco IOS Release 12.2(31)SB3.
Conditions: This symptom is seen when PPPoE/PPPoA is configured with PPP "idletimeout" and PPP keepalive.
Workaround: There is no workaround.
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Symptoms: AToM Xconnect end-to-end connectivity may be lost when MAC Address Accounting is configured on the Xconnect circuit.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 or an NSE-150.
Workaround: There is no workaround.
•
Multiple voice-related vulnerabilities are identified in Cisco IOS software, one of which is also shared with Cisco Unified Communications Manager. These vulnerabilities pertain to the following protocols or features:
–
–
–
–
–
Cisco has made free software available to address these vulnerabilities for affected customers. Fixed Cisco IOS software listed in the Software Versions and Fixes section contains fixes for all vulnerabilities mentioned in this advisory.
There are no workarounds available to mitigate the effects of any of the vulnerabilities apart from disabling the protocol or feature itself.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070808-IOS-voice.shtml.
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Symptoms: A Cisco 7301 or Cisco 7304 that is configured to use MPLS service policies on some interfaces may crash. The crash may be preceded by following error messages:
%SYS-2-CHUNKBOUNDSIB: Error noticed in the sibling of the chunk pak subblock c, Chunk index : 25, Chunk real max :25and
%SYS-2-CHUNKBADMAGIC: Bad magic number in chunk header, chunk 45FE855C data 45FE862C chunkmagic 15A3C78B chunk_freemagic 1000000Conditions: This symptom is observed on a Cisco 7301 and Cisco 7304 that run Cisco IOS Release 12.2(31)SB and is not related to a specific command sequence. However, note that the crash is platform-independent. For example, the crash could also occur on a Cisco 7600 series that runs Cisco IOS Release 12.2(33)SRB.
Workaround: There is no workaround.
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Symptoms: When QoS is applied to PPPoEoA sessions, police statistic counters may remain zero.
Conditions: This symptom is observed only on a Cisco 10000 series that has a PRE-3 and that runs Cisco IOS Release 12.2(31)SB5. The symptom does not occur in Cisco IOS Release 12.2(31)SB3.
Workaround: There is no workaround.
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Symptoms: A Cisco 7200 series may crash during bootup or while writing or erasing the configuration during the "flow_def_master_list_lookup" process.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G1 or NPE-G2. The symptom occurs during bootup or when a configuration is written to or erased from memory. The symptom may also occur when you enter the show running-config command.
Workaround: There is no workaround.
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Symptoms: A router may crash when a policy map is unconfigured.
Conditions: This symptom is observed on a Cisco router that is configured with an output policy with Frame Relay Traffic Shaping.
Workaround: There is no workaround.
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Symptoms: A PPP over Layer 2 Tunneling Protocol (PPPoL2TP) session may fail to establish itself.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3, that functions as an LNS, and that terminates PPPoL2TP tunnels.
Workaround: There is no workaround.
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Symptoms: A router may crash when it functions as a LAC with a single PPPoE session that is locally terminated and when a service policy contains CoS marking or any other non-supported configuration.
Conditions: This symptom is observed under the following conditions:
1.
2.
3.
Workaround: There is no workaround.
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Symptoms: A router that functions as an LNS and ISG may crash at the "chunk free" function when a call is being freed or disconnected.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB and is caused by a race condition. The symptom may not be release-specific.
Workaround: There is no workaround.
Further Problem Description: The following configuration suggestions may reduce the likelihood that the race condition occurs:
–
l2tp tunnel receive-window 10000
l2tp tunnel timeout hello 180–
–
aaa authentication ppp user-auth if-needed group csm-auth-acct
–
–
–
–
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Symptoms: After a microcode reload, a policy may no longer be attached to an interface.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, remove the policy from the interface and then re-attach it.
•
Symptoms: There rate of collisions and deferred packets may increase.
Conditions: This symptom is observed on a Cisco 10000 series because the Inter Packet Gap (IPG) and Inter Frame Spacing1 (IFS1) in the PRE-2 MAC register CSR125 are not set correctly.
Workaround: There is no workaround.
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Symptoms: The standby RP may enter ROMmon when the router functions in RPR+ mode.
Conditions: This symptom is observed on a Cisco 10000 series that has a 6CHT3-1 line card when you unconfigure and re-configure a Frame Relay interface under RPR+ mode.
Workaround: Do not configure RPR+. Rather, configure SSO.
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Symptoms: When L4 Redirect is configured for a traffic class with an inbound ACL only, downstream traffic may not be translated.
Conditions: This symptom is observed on a Cisco router that functions as an ISG.
Workaround: Configure both an inbound and outbound ACL for the traffic class.
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Symptoms: After a switchover has occurred, the standby PRE may reboot continuously.
Symptoms: This symptom is observed on a Cisco 10000 series when you enable and then disable the oam-ac emulation-enable command, causing a configuration mismatch between the active and standby PREs.
Workaround: There is no workaround.
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Symptoms: MLP and serial interfaces may bounce, and the following error messages may be generated:
%C10K_QUEUE_CFG_WARNING-2-EREVENT: Warning @ Bundle FIFO will not drain:5353 -Process= "PPP Events", ipl= 0, pid= 268 %C10K_MULTILINK_USER_WARNING-2-CRITEVENT: Cannot install mlp link Serial5/0/0/2:1Conditions: This symptom is observed on a Cisco 10000 series that has an MLP interface to which a service policy is attached and occurs after you have performed the following events:
1.
2.
3.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, remove and re-add the MLP interface.
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Symptoms: When the Prepaid Volume Monitor is configured to monitor PPPoX and IP sessions, reauthorizations do not occur at the required threshold expiration, and quota counts are incorrect. However, time is monitored as expected.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB6 and that functions as an ISG.
Workaround: There is no workaround.
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Symptoms: The standby PRE may reload continuously after the active PRE has crashed because of a watchdog timeout. When this situation occurs, the active PRE generates the following error message:
GET_PEER_BUFFER: Get message buffer failed.Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround. When the symptom has occurred, you must reset both PREs.
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Symptoms: A router that functions in a BBA QoS configuration may crash when a shaper policy map is removed from a PPPoEoVLAN subinterface while QoS sessions are being established.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 but may not be limited to a PRE-3.
Workaround: There is no workaround.
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Symptoms: An ATM VC may remain down until you enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface on which the ATM VC is configured.
Conditions: This symptom is observed after a service policy has been added to or deleted from the ATM VC.
Workaround: Enter the shutdown command followed by the no shutdown command on the ATM VC after the service policy has been added deleted.
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Symptoms: The standby PRE-2 may fail to boot. It may reach the standby hot state but may then reload after a "Bulk-sync failure" error is displayed on the console:
Config Sync: Bulk-sync failure due to BEM mismatchConditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB5 when SSH Version 1 (SSHv1) or SSH Version 2 (SSHv2) is configured. The symptom may be platform-independent.
Workaround: There is no workaround.
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Symptoms: All VCs that are configured on an ATM main interface may remain down until the ATM line card is reloaded.
Conditions: This symptom is observed on a Cisco 10000 series that has an ATM main interface that is administratively down when first a PRE switchover occurs and then you enter the no shutdown interface configuration command on the ATM main interface. The symptom may not be platform-specific.
Workaround: There is no workaround.
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Symptoms: A router may crash when you enter the no card command to remove the configuration of a line card.
Conditions: This symptom is observed on a Cisco 10000 series after you have removed a line card with the intention of replacing it with a line card of another type.
Workaround: There is no workaround.
TCP/IP Host-Mode Services
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Symptoms: TCP source ports that are used for connections that originate from a Cisco IOS platform may be chosen in a predictable manner.
Conditions: This symptom is observed for outbound TCP connections for which a particular source port is not required.
Workaround: There is no workaround.
Wide-Area Networking
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This caveat consist of two symptoms, two conditions, and two workarounds:
1.
Condition 1: This symptom is observed when traffic is sent through MFR interface which has or had interface fragmentation and payload compression configured. The symptom may not be platform-specific.
Workaround 1: There is no workaround. Do not configure both interface fragmentation and payload compression on an MFR interface.
2.
Condition 2: This symptom is observed with both serial Frame Relay and MFR interfaces. The symptom may not be platform-specific.
Workaround 2: Shut down the interface before you remove interface fragmentation.
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Symptoms: If non-Cisco PPPoA client is dialing into a Cisco router, the call may fail at the PPP authentication phase. When this situation occurs, the following error message is generated:
Failed to send an authentication request xConditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB5.
Workaround: There is no workaround.
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Symptoms: After an SSO switchover has occurred, some serial interfaces may remain down on the newly active RP.
Conditions: This symptom is observed on a Cisco router that has several serial interfaces with PPP encapsulation up and running on the active RP before the SSO switchover occurs.
Workaround: There is no workaround.
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Symptoms: High CPU usage may occur when IPCP is being renegotiated. Eventually, the high CPU usage may cause buffers to be backed up, may cause error message to be generated, and may cause L2TP tunnels to be dropped.
Conditions: This symptom is observed on a Cisco router when clients renegotiate IPCP unnecessarily. You can verify this situation by enabling the debug ppp negotiation command or by configuring RADIUS authorization and then checking the virtual-access interface for the phrase "cloned from: AAA, AAA, ..." (that is, multiple instances of AAA) as identification.
Workaround: There is no workaround.
Further Problem Description: You can alleviate the situation somewhat by configuring the NCP Timeout to 15 seconds to disconnect clients that take a long time to renegotiate IPCP. You can also do the following:
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This caveats consists of two symptoms, two conditions, and two workarounds:
1.
Condition 1: This symptom is observed on a Cisco 7600 series. However, the symptom may be platform-independent.
Workaround 1: Do not enter the no frame-relay map command to remove a dynamic Frame-Relay map. Rather, enter the clear frame-relay inarp command.
2.
%REDUNDANCY-3-CONFIG_SYNC: Active and Standby lbl configuration out of syncCondition 2: This symptom is observed on a Cisco 12000 series. However, the symptom may be platform-independent.
Workaround 2: Do not enter the no frame-relay map command to remove a dynamic Frame-Relay map. Rather, enter the clear frame-relay inarp command.
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Symptoms: Alternate packets may be dropped during a ping test.
Conditions: This symptom is observed when you initiate a ping over a Frame Relay PVC bundle.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB5
Cisco IOS Release 12.2(31)SB5 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB5 but may be open in previous Cisco IOS releases.
Basic System Services
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Symptoms: The Cisco IOS software image may unexpectedly restart when a crafted "msg-auth-response-get-user" TACACS+ packet is received.
Conditions: This symptom is observed after the Cisco platform had send an initial "recv-auth-start" TACACS+ packet.
Workaround: There is no workaround.
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Symptoms: IP SLA MPLS path discovery may not properly discover the number of equal-cost MPLS paths between the router on which the IP SLA MPLS path discovery originates and the router that is the target of the path discovery request.
Conditions: This symptom is observed when an IP SLA MPLS path discovery request is issued on a router for a target IP address and when some of the equal-cost paths between this router (that is, the originating router) and the target router traverse another router on which a single interface provides a connection to multiple downstream neighbors.
Workaround: Do not use a single interface to connect to multiple downstream neighbors. Rather, use separate interfaces to connect to each of the downstream neighbors.
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Symptoms: A router may crash when you unconfigure and reconfigure a RADIUS server.
Conditions: This symptom is observed on a Cisco router when you first create 5000 PPPoE sessions in a load-balancing environment, clear the sessions, unconfigure a RADIUS server, and then reconfigure a RADIUS server.
The following example shows the unconfiguring and reconfiguring of the RADIUS server:
no radius-server host
<ip-address 1> auth-port 1645 acct-port 1646 key<string>no radius-server host
<ip-address 2> auth-port 1645 acct-port 1646 key<string>radius-server host
<ip-address 3> auth-port 1814 acct-port 1815 key<string>Workaround: There is no workaround.
Interfaces and Bridging
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Symptoms: When you perform an Online Insertion and Removal (OIR) of an ATM port adapter, tracebacks are generated.
Conditions: This symptom is observed on a Cisco 7200 series when the ATM port adapter is up and has a VC configured, when traffic passes through the ATM interface of the port adapter during the OIR, and when the ATM interface of the port adapter is oversubscribed.
Workaround: There is no workaround.
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Symptoms: An ATM interface goes down after you have reloaded a router.
Conditions: This symptom is observed on a Cisco 7200 series that has a PA-A3-OC3MM port adapter but could also occur on other platforms that have an ATM port adapter.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the affected interface.
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Symptoms: Packets may become corrupted with a faulty VLAN tag when they are forwarded over an FE interface.
Conditions: This symptom is observed when the FE interface has subinterfaces that are configured for dot1q encapsulation.
Workaround: There is no workaround.
IP Routing Protocols
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Symptoms: A Cisco 7200 series may not withdraw a BGP route from an iBGP peer.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.3(3) when the clear ip bgp neighbor-address soft out command is entered for one of the members of the peer group of which the Cisco 7200 series is a member and when some changes to the outbound policy are made to the same member of the peer group. This situation causes some prefixes to remain struck in the other members of the peer group. The symptom may also occur in other releases.
The symptom is a very old behavior of the BGP peer group functionality: when one member of a peer group is cleared via either a hard reset or a soft reset and a policy change causes some of the prefixes to be withdrawn, inconsistencies may occur in the routes on the other members of the peer group.
Workaround: For peer groups and neighbors that are members of a peer group, do not enter the BGP neighbor-specific clear ip bgp neighbor-address soft out command or the clear ip bgp neighbor-address command. Rather, enter the peer group-specific clear ip bgp peer-group-name soft out command or the clear ip bgp peer-group-name command.
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Symptoms: Multipath load-balancing may not function for internal BGP (iBGP) paths, and routes are not learned through multipath routing, even after you have cleared BGP.
Conditions: This symptom is observed after an RP switchover has occurred.
Workaround: There is no workaround.
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Symptoms: A traceback may be generated when the router accesses the "bgp_vpnv4_lookup_prefix" function.
Conditions: This symptom is observed on a Cisco router that is configured for BGP VPNv4.
Workaround: There is no workaround.
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Symptoms: When you enter the maximum route VRF configuration command or reduce the limit argument of the maximum route VRF configuration command, stale routes may occur in the BGP VPNv4 table.
Conditions: This symptom is observed on a Cisco router that functions as a PE router when the connection with a CE router is configured for another protocol than BGP such as OSPF and when the routes are redistributed into BGP.
Workaround: If OSPF is the other protocol, enter the redistribute ospf address family configuration command.
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Symptoms: When a route map is configured, routes may not be filtered as you would expect them to be filtered.
Conditions: This symptom is observed on a Cisco router that is configured for BGP and that functions in an MPLS VPN environment.
Workaround: There is no workaround.
Further Problem Description: The symptom does not occur for redistributed route maps.
Miscellaneous
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Multiple voice-related vulnerabilities are identified in Cisco IOS software, one of which is also shared with Cisco Unified Communications Manager. These vulnerabilities pertain to the following protocols or features:
–
–
–
–
–
Cisco has made free software available to address these vulnerabilities for affected customers. Fixed Cisco IOS software listed in the Software Versions and Fixes section contains fixes for all vulnerabilities mentioned in this advisory.
There are no workarounds available to mitigate the effects of any of the vulnerabilities apart from disabling the protocol or feature itself.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070808-IOS-voice.shtml.
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Symptoms: The drop rate counters for an interface may show an incorrect value of 19 characters.
Conditions: This symptom is observed when you apply a service policy with traffic shaping to an interface.
Workaround: There is no workaround.
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Symptoms: CPUHOG and IPCOIR errors may occur on a Cisco router when you change the IP address of a loopback interface that is associated with a large number of active PPP sessions.
Conditions: This symptom is observed on a Cisco 10000 series that runs slowly when interfaces flap. The symptom is platform-independent.
Workaround: There is no workaround.
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Cisco uBR10012 series devices automatically enable Simple Network Management Protocol (SNMP) read/write access to the device if configured for linecard redundancy. This can be exploited by an attacker to gain complete control of the device. Only Cisco uBR10012 series devices that are configured for linecard redundancy are affected.
Cisco has released free software updates that address this vulnerability. Workarounds that mitigate this vulnerability are available.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml.
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Symptoms: Tracebacks may be logged in the console log of the standby PRE.
Conditions: This symptom is observed on a Cisco 10000 series when a T1 channel group is configured on a T3 controller of 6-port channelized T3 line card.
Workaround: Reset the standby PRE.
•
Symptoms: A Cisco 7200 series that is configured with a Port Adapter Jacket Card (C7200-JC-PA) may crash after you have performed a soft OIR of the port adapter that is installed in the Port Adapter Jacket Card.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G1 when you perform the following steps:
1.
2.
The symptom does occurs only when the not occur on a Cisco 7200 series that has an NPE-G2.
Workaround: There is no workaround.
Further Problem Description: For this caveat, while the Port Adapter Jacket Card slot address is slot 0 of the router chassis, note that the port adapter in the Port Adapter Jacket Card is identified as residing in port adapter slot 7.
•
Symptoms: A Cisco platform may reset its RP when two simultaneous write memory commands from two different vty connections are executed, and messages similar to the following may appear in the crashinfo file:
validblock_diagnose, code = 10
current memory block, bp = 0x48FCC7D8, memory pool type is Processor data check, ptr = 0x48FCC808
next memory block, bp = 0x491AC060, memory pool type is Processor data check, ptr = 0x491AC090
previous memory block, bp = 0x48FCBBE8, memory pool type is Processor data check, ptr = 0x48FCBC18The symptom is intermittent and is related to the way NVRAM is accessed.
Conditions: This symptom is observed on a Catalyst 6000 series Supervisor Engine 720 that runs Cisco IOS Release 12.2(18)SXD but is platform- and release-independent.
Workaround: Set the boot configuration to non-NVRAM media such as a disk or bootflash by entering the following commands:
boot config disk0:
filename
nvbypass
•
Symptoms: The startup configuration in NVRAM is not loaded onto line cards when the router is manually reloaded.
Conditions: This symptom is observed on a Cisco 12000 series that functions as a multiservice edge (MSE) router when the ATM Cell Relay over MPLS feature is configured on 500 connections. The symptom may also occur on other platforms.
Workaround: After the router has been reloaded, cut and paste the initially rejected configuration onto the line cards.
•
A vulnerability has been discovered in a third party cryptographic library which is used by a number of Cisco products. This vulnerability may be triggered when a malformed Abstract Syntax Notation One (ASN.1) object is parsed. Due to the nature of the vulnerability it may be possible, in some cases, to trigger this vulnerability without a valid certificate or valid application-layer credentials (such as a valid username or password).
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
The vulnerable cryptographic library is used in the following Cisco products:
–
–
–
–
–
This vulnerability is also being tracked by CERT/CC as VU#754281.
Cisco has made free software available to address this vulnerability for affected customers. There are no workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-crypto.shtml.
Note
•
Two crafted Protocol Independent Multicast (PIM) packet vulnerabilities exist in Cisco IOS software that may lead to a denial of service (DoS) condition. Cisco has released free software updates that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080924-multicast.shtml.
•
Symptoms: A router may crash because of a bus error when you enter the copy scp command to copy a configuration.
Conditions: This symptom is observed on a Cisco router that is configured for SSH.
Workaround: Do not use SCP. Rather, use Remote Copy Protocol (RCP) or use a TFTP transfer.
•
Symptoms: Malformed SSH version 2 packets may cause a memory leak, causing the platform to operate under a degraded condition. Under rare circumstances, the platform may reload to recover itself.
Conditions: This symptom is observed on a Cisco platform that is configured for SSH version 2 after it has received malformed SSHv2 packets.
Workaround: As an interim solution until the affected platform can be upgraded to a Cisco IOS software image that contains the fix for caveat CSCse24889, configure SSH version 1 from the global configuration mode, as in the following example:
config t
ip ssh version 1
endAlternate Workaround: Permit only known trusted hosts and/or networks to connect to the router by creating a vty access list, as in the following example:
10.1.1.0/24 is a trusted network that
is permitted access to the router, all
other access is deniedaccess-list 99 permit 10.1.1.0 0.0.0.255
access-list 99 deny anyline vty 0 4
access-class 99 in
endFurther Problem Description:
For information about configuring vty access lists, see the Controlling Access to a Virtual Terminal Line document:
http://www.cisco.com/en/US/products/ps6441/
products_configuration_guide_chapter09186a0080716ec2.htmlFor information about SSH, see the Configuring Secure Shell on Routers and Switches Running Cisco IOS document:
http://www.cisco.com/warp/public/707/ssh.shtml
•
Symptoms: A policing error may occur on a DHCP IP session when local authorization is configured.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Configure a DHCP IP session and RADIUS authorization.
•
A device running Cisco IOS software that has Internet Protocol version 6 (IPv6) enabled may be subject to a denial of service (DoS) attack. For the device to be affected by this vulnerability the device also has to have certain Internet Protocol version 4 (IPv4) User Datagram Protocol (UDP) services enabled. To exploit this vulnerability an offending IPv6 packet must be targeted to the device. Packets that are routed throughout the router can not trigger this vulnerability. Successful exploitation will prevent the interface from receiving any additional traffic. The only exception is Resource Reservation Protocol (RSVP) service, which if exploited, will cause the device to crash. Only the interface on which the vulnerability was exploited will be affected.
Cisco is providing fixed software to address this issue. There are workarounds available to mitigate the effects of the vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080326-IPv4IPv6.shtml.
•
Symptoms: When you apply an input service policy to an AToM PVC, a router may reload and generate the following error message and traceback:
Unexpected exception to CPUvector 300, PC = 119B6D0
-Traceback= 119B6D0 118E2F8 5952270 118FDC4 11B7680 11B78EC 236988 24BDD4 2E95CCConditions: This symptom is observed on a Cisco 12000 series that runs Cisco IOS Release 12.0(32)S3 but is platform- and release-independent. The symptom occurs when you enter the following commands:
Router(config)#interface x/y.z point-to-point
Router(config-subif)# no ip directed-broadcast
Router(config-subif)# no atm enable-ilmi-trap
Router(config-subif)# pvc a/b l2transport
Router(cfg-if-atm-l2trans-pvc)# encapsulation aal5
Router(cfg-if-atm-l2trans-pvc)# xconnect a.b.c.d xy encapsulation mpls
Router(cfg-if-atm-l2trans-pvc-xconn)#Router(cfg-if-atm-l2trans-pvc-xconn)#service-policy test
Workaround: There is no workaround.
•
Symptoms: A router crashes when PPPoEoA sessions are torn down.
Conditions: This symptom is observed when the maximum number of class-map instances are configured on the router.
Workaround: There is no workaround.
•
Symptoms: High CPU use may occur in the "IP Background" process, and the router may reload unexpectedly.
Conditions: This symptom is observed on a Cisco router that is configured for RIP and that receives a RIP host route that is subsequently replaced by a route that is dynamically assigned to an interface. For example, this situation may occur on a PPP interface that has the ip address negotiated command enabled.
Workaround: Use a route map to block the advertised route.
•
Symptoms: When you enter the issu loadversion command, the ISSU mail fail with the following error message:
Active [ ] and Standby [ ] images should be the same for running loadversionConditions: This symptom is observed in a rare situation on a Cisco router and occurs even when the Cisco IOS software images on the active and standby RPs are identical.
Workaround: There is no workaround.
•
Symptoms: A ping from one CE router to another CE router through an AToM tunnel does not go through properly.
Conditions: This symptom is observed on a Cisco router when the AToM tunnel runs over two different autonomous systems.
Workaround: There is no workaround.
•
Symptoms: Load-sharing on core links may not function.
Conditions: This symptom is observed on a Cisco router that functions in an AToM configuration with multiple VCs, with traffic flowing through each VC, and with multiple equal-cost paths to the core.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series may drop MPLS packets from an ingress interface.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(28)SB or a later release after an FSU has occurred on a neighboring router.
Workaround: Enter the microcode reload pxf command on the Cisco 10000 series.
•
Symptoms: In an ATM pseudowire configuration, when you reset a line card by entering the hw-module slot slot-number reset command, the pseudowire comes back up but the traffic does not resume, and an end-to-end ping fails.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface of the line card that was reset.
•
Symptoms: A router may crash when the dynamic ACL timer expires.
Conditions: This symptom is observed on a Cisco router only when the show access-list command is entered before the timer expires.
Workaround: There is no workaround.
•
Symptoms: Frame Relay end-to-end keepalives may unexpectedly time out.
Conditions: This symptom is observed on a Cisco 7206VXR that has an NPE-G1 and that runs Cisco IOS Release 12.2(31)SB2.
Workaround: There is no workaround.
•
Symptoms: Some serial interfaces continuously flap and do not remain in the up state because a PPP negotiation loop occurs.
Conditions: This symptom is observed on a Cisco 10000 series after a large number of interfaces has flapped from more than two hours.
Workaround: There is no workaround.
•
Symptoms: A multicast ping may be dropped by a Cisco 7304.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 or NSE-150 when the router attempts to respond to the ping. The symptom does not occur for traffic that traverses the router.
Workaround: There is no workaround.
•
Symptoms: A Cisco 7304 may stop passing traffic through its Gigabit Ethernet interfaces. Even though a show command shows that the interfaces continue to be in the up/up state and respond to removal of the network cable, no traffic is transmitted from the interfaces. The CPU usage of the PXF engine may reach 100 percent, or at least higher than you would reasonably expect.
Conditions: This symptom is observed on a Cisco 7304 with an NSE-100 or NSE-150 when there are input and output ACLs configured and when ACL output deny drops occurs. In this situation, the PXF engine attempts to generate ICMP unreachables, some of which are looping continuously in the PXF engine, causing the CPU usage of the PXF engine to be high.
Workaround: Disable ICMP unreachables on the interfaces by entering the no ip unreachable command. Doing so prevents the CPU usage of the PXF engine from becoming higher but does not decrease its current level. To enable the CPU usage of the PXF engine to return to a normal level, reload the router after you have disabled ICMP unreachables on the interfaces.
•
Symptoms: A Cisco 10000 series may generate a traceback when you attempt to create a duplicate IP session.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an Intelligent Service Gateway (ISG) and occurs only with IP sessions that are connected via Layer 2. The symptom occurs because of a timing issue.
Workaround: There is no workaround.
•
Symptoms: Some E1 channels may remain down after you have reloaded a router.
Conditions: This symptom is observed on a Cisco 7200 series that function as a PE router and that connects to a CE router. Both routers are connected through 1-port multichannel STM-1 (PA-MC-STM-1) port adapters and the framing no-crc4 command is enabled on all interfaces of both routers.
Workaround: Enter the shutdown command followed by the no shutdown command on the SONET controller of the PA-MC-STM-1 at the PE side to enable all interfaces to come up.
•
Symptoms: When a SmartJack is configured in a loopback, the PRE in slot B of a Cisco 10000 series may crash continuously because bulk synchronization fails between the PREs.
Conditions: This symptom is observed when you enter the t1 t1-number loopback remote line inband maintenance command.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, remove all occurrences of the t1 t1-number loopback remote line inband maintenance command from the running configuration via the console of the active PRE.
•
Symptoms: After creating T1 links on a channelized STM-1 interface, you cannot access the associated interfaces in global configuration mode or Exec mode.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Creating a new interface may clear the condition. If it does not, reload the router.
•
Symptoms: When the ip cef command is enabled, output bytes of a virtual-access interface do not increment correctly.
Conditions: This symptom is observed on a Cisco router that has a PPPoVPDN virtual-access interface when the VPDN traffic is sent over an ATM interface. The symptom does not occur when the VPDN traffic is sent over a Gigabit Ethernet interface.
Workaround: If this is an option, disable CEF on the interface from which the VPDN traffic is switched. However, doing so may affect the performance of the platform. If this is not an option, there is no workaround.
•
Symptoms: The following symptoms may occur for prepaid accounting:
–
...
RADIUS(0000000D): Send Accounting-Request to 10.30.81.45:1813 id 21651/19, len 391
RADIUS: authenticator 6C 91 FF EE 94 43 4A 76 - 8A FD 94 53 66 E3 53 25
RADIUS: Acct-Session-Id [44] 18 "0A0A440200000003"
...
RADIUS: Acct-Input-Giga-Word[52] 6 1
RADIUS: Acct-Output-Giga-Wor[53] 6 0–
...
(0000000D): Send Accounting-Request to 10.30.81.45:1813 id 21651/20, len 299
RADIUS: authenticator 0A C2 61 78 C9 63 04 64 - 6E C4 F4 B3 11 E9 DF A4
RADIUS: Acct-Session-Id [44] 18 "0A0A440200000004" [1]
RADIUS: Cisco AVpair [1] 36 "parent-session-id=0A0A440200000003"
RADIUS: Vendor, Cisco [26] 21
RADIUS: ssg-control-info [253] 15 "I0;2017511512"Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB3 and that is configured with a prepaid service policy.
Workaround: There is no workaround.
•
Symptoms: A router crashes when you configure a local ISG service policy with any routing protocol such as BGP or ISS.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB3 when you enter the following commands:
Router(config)#router bgp 1
Router(config-router)#service
Router(config-router)#policy-map type service <policy-map-name>
Router(config-service-policymap)#service local
Workaround: Configure and download service profiles via a RADIUS server.
•
Symptoms: The PXF engine may crash many times on a Cisco 10000 series that is functions as an L2TP Network Server (LNS). Each time that the PXF engine crashes, the following error message is generated:
PXF DMA Error - Input Command Has Sequence Problem.This situation may cause the router to crash (that is, a software-forced crash may occur).
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2 or PRE-3 and that runs Cisco IOS release 12.2(31)SB or one of its rebuilds when packets arrive on an L2TP tunnel and when the inner IP packet is destined for the router. This means that the destination address of the user packet that is carried within the L2TP tunnel is a local address on the LNS. One example of this condition is a keepalive message that is used between the subscriber and the LNS.
Workaround: The router crashes because IP packets with an L3-destination address are sent to the router over PPP sessions. For packets that arrive on L2TP tunnels, deny access to the IP addresses of the router: on the LNS, configure an input ACL on the virtual template to deny IP access to all router interfaces.
•
A vulnerability in the Cisco implementation of Multicast Virtual Private Network (MVPN) is subject to exploitation that can allow a malicious user to create extra multicast states on the core routers or receive multicast traffic from other Multiprotocol Label Switching (MPLS) based Virtual Private Networks (VPN) by sending specially crafted messages.
Cisco has released free software updates that address this vulnerability. Workarounds that mitigate this vulnerability are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080326-mvpn.shtml.
•
Symptoms: A router may crash when a DLCI configuration is removed from an MFR subinterface.
Conditions: This symptom is observed on a Cisco 7200 series when the MFR interface has a map class with a service policy attached.
Workaround: There is no workaround.
•
Symptoms: After a PRE switchover has occurred, a PPP interface may not come up. This situation may occur when the PPP interface was shut down and brought up but remained in the up/down state before the PRE switchover occurred.
Conditions: This symptom is observed on a Cisco 10000 series. When the output of the show ppp interface command does not show a PPP handle, as in the example below, the symptom has occurred:
router#show ppp int p1/0/0
PPP Serial Context Info
Interface : PO1/0/0
PPP Serial Handle: 0x0
PPP Handle : 0x0
SSS Handle : 0x0
AAA ID : 16
Access IE : 0x0
State : Down
Last State : Init
Last Even : CstateUpWorkaround: After the PRE switchover has occurred, change the interface protocol from PPP to HDLC and then back to PPP to assign a new handle to the interface, as in the following example:
conf t
int p1/0/0
encap hdlc
encap ppp
end•
Symptoms: A Cisco 7200 series with an NPE-G2 may hang during the boot process.
Conditions: This symptom is observed when several native Gigabit Ethernet ports with "MV64460" hardware come up simultaneously, for example, while he router boots. To verify if the Gigabit Ethernet ports of your router have "MV64460" hardware, look in the output of the show interfaces command.
Workaround: There is no workaround.
•
Symptoms: A new PRE may restart in a continuous loop when you insert it in the standby slot.
Conditions: This symptom is observed on a Cisco 10000 series when the PRE in the active slot runs a Cisco IOS software image that includes the fix for caveat CSCsf10723.
A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsf10723. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround.
•
Symptoms: An end-to-end ping between CE routers may fail in an ATMoMPLS environment.
Conditions: This symptom is observed when a Cisco router that functions as a PE router has ATMoMPLS configured as "ATM single cell relay over MPLS: port mode" via the xconnect command under an ATM Main interface.
Workaround: There is no workaround.
•
Symptoms: A Cisco 7304 that has an NSE-100 may crash when you unconfigure a match statement in a class map.
Conditions: This symptom is observed on a Cisco 7304 that runs Cisco IOS Release 12.2(31)SB when you enter the no match ip prec twice for a class map.
Workaround: There is no workaround.
•
Symptoms: The PXF engine of a Cisco 10000 series may crash and the following error message may be generated:
%C10KEVENTMGR-1-MAJOR_FAULT: PXF DMA FTC Move Command with Continue Error PXF DMA Error - Input Command Has Sequence Problem, Restarting PXFConditions: This symptom is observed on a Cisco 10000 series that functions as an LNS and that is configured for NetFlow.
Workaround: Disable NetFlow.
•
Symptoms: The statistics that are shown in the output of the show policy-map session uid uid-number command are not correct for LAC sessions that have QoS enabled.
Conditions: This symptom is observed on a Cisco 10000 series that runs a Cisco IOS software image that has the fix for caveat CSCsc23981 integrated. A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsc23981. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround.
•
Symptoms: Even after you have removed a T1 line, you still can configure a Facilities Data Link (FDL) on the removed T1 line by entering the service-module t1 fdl command. This command should not be accepted since the T1 line is not available.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
•
Symptoms: A router may crash and generate the following error messages:
%SYS-2-CHUNKBOUNDSIB: Error noticed in the sibling of the chunk pak subblock
-Process= "LFDp Input Proc" %SYS-2-CHUNKBADMAGIC: Bad magic number in chunk header, chunk
-Process= "LFDp Input Proc" %Software-forced reloadConditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB2 and that is configured for MPLS.
Workaround: There is no workaround. Note that the symptom does not occur in Release 12.2(28)SB5.
•
Symptoms: The Cisco IOS software image on a Cisco 10000 series may unexpectedly reload because of repeated crashes of the PXF engine.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2 and an MLP configuration. The PXF engine may crash each time it reboots, generating more PXF crashinfo files. Eventually, the Cisco IOS software image reloads.
Workaround: Remove the MLP configuration and/or isolate the router from MLP traffic. If this is not an option, there is no workaround.
•
Symptoms: The PXF engine may continuously crash on a Cisco 10000 series.that has a PRE-3.
Conditions: This symptom is observed on a Cisco 10000 series that has an output policer configured on the egress interface when IP packets with a precedence values of 6 are forwarded and when the traffic rate exceeds the value that is configured in the policer.
Workaround: There is no workaround.
•
Symptoms: PPP may crash when an snmpwalk command is executed on the cbQosSetStatsTable object.
Conditions: This symptom is observed when a service policy with a child policy that contains marking ("set") actions is applied to an interface before the snmpwalk command is executed on the cbQosSetStatsTable object of the CISCO-CLASS-BASED-QOS-MIB.
Workaround: There is no workaround.
Wide-Area Networking
•
Symptoms: Sessions and login authentication may fail on a Cisco 10000 series when a memory allocation (malloc) error occurs that causes the available memory to become low.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for PPPoATM or PPPoEoA when you attempt to change QoS values multiple times with a large number of CoA request for the same session. The symptom does not occur when QoS values are changed a single time or a few times for the same session.
Workaround: There is no workaround.
•
Symptoms: UDP port 1701 (for L2TP) is opened by a port scan. The router does not send a "port unreachable" message for a packet that uses UDP port 1701.
Conditions: This symptom is observed on a Cisco 1812 router that runs Cisco IOS Release 12.3(14)YT or Release 12.4(2)T1 but may also occur in other releases.
Workaround: There is no workaround.
•
Symptoms: When a PPPoE server receives a second PADI from a client (that is, a PADI with the same unique client ID), the PPPoE server may send a PADS with an unknown MAC address.
Conditions: This symptom is observed on a Cisco platform that functions as a PPPoE server that has established a PPPoE session with a client and occurs while PPP LCP negotiation is in progress.
Workaround: There is no workaround.
•
Symptoms: A router may reload while displaying the output of the show ppp multilink command.
Conditions: This symptom is observed when the multilink bundle goes down while the output is being displayed.
Workaround: There is no workaround.
•
Symptoms: Both accounting START and STOP records are not sent to a RADIUS server after an LNS failover has occurred.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an LNS in a VPDN failover configuration with multihops and that is connected to a RADIUS server. The symptom occurs in a topology in which the LAC has access to both LNS platforms when the first LNS is not accessible but the second LNS is accessible.
Workaround: There is no workaround.
Open Caveats—Cisco IOS Release 12.2(31)SB3
Cisco IOS Release 12.2(31)SB3 is a rebuild release for Cisco IOS Release 12.2(31)SB2. This section describes a severity 1 caveat that is open in Cisco IOS Release 12.2(31)SB and its rebuilds. There are other open caveats in Cisco IOS Release 12.2(31)SB3. However, open caveats are normally listed only for maintenance releases, and the listing of CSCsh94923 and CSCsi18240 is an exception.
Miscellaneous
•
Symptoms: The PXF engine may crash many times on a Cisco 10000 series that is functions as an L2TP Network Server (LNS). Each time that the PXF engine crashes, the following error message is generated:
PXF DMA Error - Input Command Has Sequence Problem.This situation may cause the router to crash (that is, a software-forced crash may occur).
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2 or PRE-3 and that runs Cisco IOS release 12.2(31)SB or one of its rebuilds when packets arrive on an L2TP tunnel and when the inner IP packet is destined for the router. This means that the destination address of the user packet that is carried within the L2TP tunnel is a local address on the LNS. One example of this condition is a keepalive message that is used between the subscriber and the LNS.
Workaround: The router crashes because IP packets with an L3-destination address are sent to the router over PPP sessions. For packets that arrive on L2TP tunnels, deny access to the IP addresses of the router: on the LNS, configure an input ACL on the virtual template to deny IP access to all router interfaces.
•
Symptoms: After receiving packets through an L2TP tunnel and decapsulating these packets, a Cisco 10000 series may corrupt certain packets.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB3. There is a two-byte window for packets that are corrupted:
–
–
Workaround: There is no workaround.
Further Problem Description: The symptom occurs only in Release 12.2(31)SB3 and does not affect other releases.
Resolved Caveats—Cisco IOS Release 12.2(31)SB3
Cisco IOS Release 12.2(31)SB3 is a rebuild release for Cisco IOS Release 12.2(31)SB2. The caveats in this section are resolved in Cisco IOS Release 12.2(31)SB3 but may be open in previous Cisco IOS releases.
Basic System Services
•
Symptoms: When a new PPP session is set up, the following warning message is generated, and the session fails:
LAC: %IDMNGR-3-ALLOCFAIL: Warning: Failed to allocate memory for keylist in event_initConditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB1. The PPP sessions start failing after the router has been up for about two weeks with many policy-map changes on the PVCs, a few cleared sessions by the clients, and one switchover.
Workaround: There is no workaround.
•
Symptoms: A Cisco 10000 series may run out of memory after a number of ATM port flaps have occurred.
Conditions: This symptom is observed on a Cisco 10000 series that is configured with 28,000 PPPoA Point-to-Point Termination and Aggregation (PTA) sessions. Each time that the ATM ports that carry the sessions flap and in this process remain down long enough for the sessions to time-out, more memory is lost.
Workaround: There is no workaround.
•
Symptoms: A packet of disconnect (POD) does not disconnect a user. When you enable the debug aaa pod command, the output shows the following:
POD: Added Reply Message: No Matching Session
POD: Added NACK Error Cause: Session Context Not FoundConditions: This symptom is observed on a Cisco 10000 series that is configured for AAA when the Account-Session-Id is prepended with information. For example, if the Account-Session-Id is "7/0/0/1.40_00000039" in a POD, the POD fails to find a match.
Workaround: If the Account-Session-Id is "7/0/0/1.40_00000039", configure the POD application to take only the eight right digits: "00000039".
•
Symptoms: A TLB exception may occur on a Cisco platform that functions as a PE router in an MPLS environment, and the following error message may be generated:
TLB (load or instruction fetch) exception, CPU signal 10 (BadVaddr: DEADBEF3)Conditions: This symptom is observed on a Cisco platform when TACACs accounting and authorization is enabled and when the TACACs server is reachable through the global routing table.
Workaround: Disable AAA. Is this not an option, there is no workaround.
•
Symptoms: A Cisco 10000 series may crash and generate an "%C10K-2-RPRTIMEOUT_CRASH:" error message.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for NetFlow.
Workaround: There is no workaround.
EXEC and Configuration Parser
•
Symptoms: When you enter the write memory command, the following error message and a traceback are generated:
Router#wr Building configuration...
% String too long to write to nvram (2578):Compressed configuration from 3452120 bytes to 786685 bytes[OK] Uncompressed configuration from 786685 bytes to 3452120 bytesConditions: This symptom is observed on a Cisco router when the configuration is saved after you have entered the parser config cache interface command.
Workaround: Disable the no parser config cache interface command.
Interfaces and Bridging
•
Symptoms: A ping from a channelized T3 (CT3) port adapter may fail.
Conditions: This symptom is observed on a Cisco platform that is configured with a CT3 port adapter that functions in unchannelized mode.
Workaround: There is no workaround.
IP Routing Protocols
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Symptoms: External BGP neighbors that are configured in the IPv4 VRF address-family context may fall into different update groups, even if the outbound policy is identical. This situation slightly reduces the overall scalability because BGP cannot use update replication when sending updates to the neighbors.
Conditions: This symptom is observed on a Cisco router and is both release- and platform-independent.
Workaround: There is no workaround.
Further Problem Description: The symptom does not affect neighbors that are configured in the global IPv4 address-family context.
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Symptoms: PIM may not choose the path with the highest IP address when it should do so.
Conditions: This symptom is observed on a Cisco router that functions in a topology with equal-cost RPF paths.
Workaround: There is no workaround.
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Symptoms: Many "IPRT-3-PATHIDX" error messages are generated by the "BGP Router" process when you increase the prefixes in a VRF.
Conditions: This symptom is observed on a Cisco router that is configured for loadbalancing and that functions in an MPLS VPN environment.
Workaround: There is no workaround.
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Symptoms: A router may crash when you remove an unused and unassigned VRF by entering the no ip vrf vpn-name command.
Conditions: This symptom is observed on a Cisco router that functions as a PE router and that has the Multi-VRF capability for OSPF routing configured along with other VRFs that are unused and unassigned.
Workaround: There is no workaround.
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Symptoms: When you enter the no ip nat service skinny tcp port 2000 command, NAT is not disabled on port 2000. This situation causes NAT to be applied to SCCP packets, and causes the CPU usage to be very high.
Conditions: This symptom is observed when an application is running on the port 2000.
Workaround: There is no workaround.
Further Problem Description: SCCP and NAT for voice are not supported in Cisco IOS Release 12.2 or a release that is based on Release 12.2. The no ip nat service skinny tcp port 2000 command is not supported in these releases.
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Symptoms: ARP may be refreshed excessively on the default interface, causing high CPU usage in the "Collection Process."
Conditions: This symptom is observed on a Cisco router that has point-to-point interfaces that have non-/32 interface addresses or secondary addresses and that constantly come up or go down.
Workaround: There is no workaround.
ISO CLNS
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Symptoms: When IS-IS and CLNS are configured, a router may enter a state in which only one adjacency is shown in the output of the show clns interface command, even though the show clns neighbors command may correctly display all the neighbors that are connected to the interface.
When this situation occurs and any one of the neighbors on the segment goes down, all routing updates may be lost. The single adjacency is torn down and despite the fact that the output of the show clns neighbors command still shows the neighbors, routing stops because there are no adjacencies.
Conditions: This symptom is observed when an adjacency goes down while it is still in the INIT state. The symptom occurs because the adjacency counter is incorrectly decremented.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface that reports only one adjacency.
Alternate Workaround: Enter the clear clns neighbors command on the affected router.
Miscellaneous
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Symptoms: A router crashes when you add a new SONET-related interface.
Conditions: This symptom is observed on a Cisco router when no more memory is available.
Workaround: There is no workaround.
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Symptoms: A Cisco 7304 crashes when you configure an SVC, unconfigure the SVC, configure a VC, and unconfigure the VC.
Conditions: This symptom is observed on a Cisco 7304 when you perform the following actions:
1.
2.
3.
no ip routing
no ip address ip-address mask
no atm pvc vcd vpi vci
aal5snap inarp minutes
At this point, the router crashes.
Workaround: Do not unconfigure a VC by using the method that is indicated in the Conditions above.
Alternate Workaround: When the router has the atm bandwidth dynamic command enabled for an IMA group, remove this command to prevent the router from crashing.
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Symptoms: The running configuration may not be accessible after you have copied a small file to the running configuration.
Conditions: This symptom is observed on a Cisco router that has an ATA file system after you have rebooted the router.
Workaround: Reboot the router once more.
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Symptoms: A standby RP may reload repeatedly when you enter the issu loadversion command during a period of high checkpointing activity. When you enter the show checkpoint statistics command on the active RP, the output shows that the checkpointing IPC flow control status remains set to zero indefinitely:
CHKPT FLOW_ON status = 0Conditions: This symptom is observed on a Cisco router when the standby RP reloads as part of the In-Service Software Upgrade (ISSU) process while, for example, a large number of PPPoA sessions are being disconnected.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, enter the issu abortversion command to cancel the ISSU process, and then reload the router.
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Symptoms: Spurious memory accesses may occur on a Cisco 10000 series that is configured for PPPoA.
Conditions: This symptom is observed when you first add and then remove Variable Bit Rate (VBR) from a VC class for active PPPoA sessions.
Workaround: There is no workaround.
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Symptoms: The police counters are not properly incremented after a class has been added or deleted.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB2 when the total number of classes crosses a power-of-2 boundary after a class has been added to or deleted from the policy that is attached to an interface.
For example, the symptom occurs under the following conditions:
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Workaround: Detach the service policy from the interface, add or delete a class to or from the policy, and re-attach the policy.
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Symptoms: When you continuously perform OIRs of a SPA or port adapter that is installed in a Port Adapter Carrier Card, tracebacks are generated, and the router eventually crashes.
Conditions: This symptom is observed on a Cisco 7304 that is configured for HA.
Workaround: There is no workaround.
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Symptoms: When you first reset the standby RP and then a switchover occurs, the following error message and a traceback are generated:
%LFD-3-ORPHANNONIPLTE: Found a non-owned non-IP LTE of ptype 5 - label 0/0.Conditions: This symptom is observed on a Cisco router that is configured for MPLS.
Workaround: There is no workaround.
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Symptoms: After a microcode reload has occurred, traffic is dropped for all users that have a per-user ACL configured and for which the user IP address is specified in the ACL.
Conditions: This symptom is observed on a Cisco 10000 series when a per-user ACL is applied to each session and when an ACL Template is enabled.
Workaround: After you have performed a microcode reload, disconnect and reconnect all sessions. Note that it is very likely that a user will reconnect a session after traffic has dropped.
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Symptoms: The Lawful Intercept feature may not function for active tapped sessions after a microcode reload has occurred. Tapping works fine for new sessions that come up after the microcode reload has occurred.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Disconnect and reconnect the existing active tapped sessions after the microcode reload has occurred.
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Symptoms: MFR interfaces do not come up when the router boots.
Conditions: This symptom is observed on a Cisco 10000 series that runs a Cisco IOS software image that includes the fix for CSCsg86572 and that has MFR interfaces configured on either a 1 port channelized OC-12 line card or a 4-port channelized OC-3 line card. A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg86572. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround.
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Symptoms: A Cisco 7304 may reload unexpectedly because of a watchdog reset condition, which can be seen in the output of the show version command.
Conditions: This symptom is observed only on a Cisco 7304 that has an NPE-G100.
Workaround: There is no workaround.
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Symptoms: A ping does not work when a loopback is configured on an interface.
Conditions: This symptom is observed on a Cisco 7200 series, Cisco 7500 series, and Cisco 7600 series that are configured with a T3 interface.
Workaround: There is no workaround.
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Symptoms: A router crashes when a non-VLAN user class is configured under a parent policy with an action such as the set qos-group command.
Conditions: This symptom is observed on a Cisco 10000 series and occurs because a non-VLAN user class under a parent policy is an illegal configuration.
Workaround: Do not configure a non-VLAN user class under a parent policy. However, note that you can configure a VLAN user class under a parent policy.
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Multiple voice-related vulnerabilities are identified in Cisco IOS software, one of which is also shared with Cisco Unified Communications Manager. These vulnerabilities pertain to the following protocols or features:
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Cisco has made free software available to address these vulnerabilities for affected customers. Fixed Cisco IOS software listed in the Software Versions and Fixes section contains fixes for all vulnerabilities mentioned in this advisory.
There are no workarounds available to mitigate the effects of any of the vulnerabilities apart from disabling the protocol or feature itself.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070808-IOS-voice.shtml.
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Symptoms: Continuous CPUHOGs may occur during the "ATM OAM Input" process, locking the console for a long time.
Conditions: This symptom is observed on the MSFC of a Cisco 7600 series that runs Cisco IOS Release 12.2(33)SRA and that has an ATM interface with several VCs that are configured for Single Cell Relay (VC Mode). These VCs are configured on a PA-A3-OC3 or PA-A6-OC3 port adapter that is installed in an enhanced FlexWAN module. The symptom occurs after the peer router that is connected to the ATM interface (and on which the PVPs are configured) is reloaded.
Note that the symptom is not platform- or release-dependent.
Workaround: When the console is less busy, shut down the ATM interface on the peer router. The CPUHOGs may stop after some time. If this is not an option, there is no workaround.
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Symptoms: A memory leak may occur when you remove an Xconnect configuration from a router, which can be verified by enabling the show memory debug command.
Conditions: This symptom is observed when you configure Xconnect with the Exchange Fabric Protocol (EFP) and then remove the Xconnect configuration.
Workaround: There is no workaround.
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Symptoms: When you configure the C2 overhead byte under SONET T3 or VT controllers on a 1-port channelized OC-12/STM-4 or 4-port channelized STM-1/OC-3 line card, the T3 or VT controllers may not come up.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: DHCP control messages that are sent by a DHCP relay agent and that are destined for an external DHCP server do not pass through an interface of an Intelligent Service Gateway (ISG).
Conditions: This symptom is observed on a Cisco router that functions as an ISG when the interface is configured for IP Session Creation.
Workaround: There is no workaround.
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Symptoms: When a hierarchical policy with CoS is configured, traffic shaping that is applied on the parent policy does not function properly for speeds that are slower than 2000 kbps because the throughput is reduced.
Conditions: This symptom is observed on a Cisco 7304 when there is a priority class configured in a policy that is attached to an interface. The larger the packets, the more the throughput is reduced.
Workaround: There is no workaround.
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Symptoms: A router may reload unexpectedly when you enter the show mpls ldp graceful-restart command.
Conditions: This symptom is observed when either of the following conditions are present:
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Workaround: Do not enter the show mpls ldp graceful-restart command when a graceful-restart database entry is about to expire. When the command output is paged at the "--More--" string within the context of displaying addresses and when the Down Neighbor Database entry may have expired, type the letter "Q" to abort any further output of addresses.
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Symptoms: When traffic is being processed at a low speed such as 56 Kbps, intermittently, traffic comes to a complete halt on a Frame Relay subinterface.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2. The symptom occurs when the PXF engine stops dequeueing packets on the Frame Relay subinterface, causing the interface output queue to become wedged.
Workaround: Remove the service policy from the subinterface and then re-apply the service policy to the subinterface.
Further Problem Description: Without applying the workaround, about 60 to 70 minutes after the output queue has become wedged, the output queue starts to dequeue itself.
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Symptoms: A DHCP route is unexpectedly removed for an unnumbered DHCP binding.
Conditions: This symptom is observed when a DHCP address is renewed.
Workaround: There is no workaround. However, during the next DHCP address renewal, the DHCP route is added back.
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Symptoms: High CPU usage may occur during the "XDR mcast" and "XDR RP" background processes. Each of these processes uses more than 30 percent of the CPU while no data traffic passes through the router.
Conditions: This symptom is observed on a Cisco 10000 series but is platform-independent.
Workaround: Reload the router.
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Cisco 10000, uBR10012 and uBR7200 series devices use a User Datagram Protocol (UDP) based Inter-Process Communication (IPC) channel that is externally reachable. An attacker could exploit this vulnerability to cause a denial of service (DoS) condition on affected devices. No other platforms are affected.
Cisco has released free software updates that address this vulnerability. Workarounds that mitigate this vulnerability are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080924-ipc.shtml.
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Symptoms: A router may crash when a policy map that is in use by sessions is modified while the sessions are disconnected.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 but may not be limited to this platform.
Possible Workaround: Clear all sessions before you modify the policy map.
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Symptoms: A DHCP-initiated IP subscriber session may not respond to DHCP control packets.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG) when the subscriber session has features enabled that affect the handling of the DHCP control packets.
Workaround: Apply access control lists (ACLs) to the subscriber session to permit bidirectional DHCP control traffic between the ISG and the DHCP client. To do so, enter the access-list access-list-number permit udp any any eq bootps command.
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Symptoms: When a prepaid service is unapplied from rules, the accounting stop record does not contain packet counts and octet counts.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG) when the service-policy type service unapply name policy-map-name command (in which the policy-map-name argument indicates the prepaid service) is configured in the rules.
Workaround for the packet counts: There is no workaround.
Workaround for the octet counts: Look for the information in the following attributes that are present in the according stop record:
ssg-control-info [253] 6 "I<high>;<low>" <low> indicates the input octets.
ssg-control-info [253] 6 "O<high>;<low>" <low> indicates the output octets.•
Symptoms: During dynamic VLAN class modifications, the queueing policy inheritance fails. This situation causes traffic to be dropped.
Conditions: This symptom is observed on a Cisco 10000 series that has a hierarchical queueing policy for VLAN classes and a flat shaper for the class default. When the VLAN class modifications occur that shift the matching subinterfaces to the class default, then back to the original VLAN class, and then to another VLAN class, the child queues are not created, causing traffic to drop.
Workaround: Remove and re-attach the hierarchical queueing policy.
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Symptoms: Non-Priority Queuing (PQ) traffic in a class default in a QoS policy that includes the match vlan command is not dequeued during oversubscription of the PQ class.
Conditions: This symptom is observed on a Cisco 10000 series only when there are multiple VLAN classes and when there are child queueing policies in the class default and the VLAN classes. The PQ policer takes the interface bandwidth as reference, causing policing to occur at the wrong rates and starvation of non-PQ child classes in the class default. The symptom does not occur for child classes in a VLAN class.
Workaround: There is no workaround.
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Symptoms: Traffic stops matching to a child policy.
Conditions: This symptom is observed on a Cisco 10000 series when an interface has a hierarchical policy defined on a PVC, when you remove the child policy, and when you re-attach the child policy to the parent policy of the hierarchical policy. In this situation, the traffic no longer matches to the child policy.
Workaround: Detach the hierarchical policy from the PVC, modify the child policy, and re-attach the hierarchical policy to the PVC.
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Symptoms: Temperature alarms on a Cisco 10000 series PRE-3 assert at lower ambient temperatures than necessary.
Conditions: This symptom may occur in an operating environment in which the ambient temperature is in the low 30s (degrees Celsius).
Workaround: You can reprogram the temperature alarm thresholds. The recommended thresholds are:
inlet minor: 41 C
inlet major: 51 C
inlet critical: 73 C
outlet minor: 48 C
outlet major: 58 C
outlet critical: 85 C•
Symptoms: When the standby PRE comes up, the following error message is generated on the console of the active PRE:
REDUNDANCY-3-IPC: cannot open standby port session in useConditions: This symptom is observed on a Cisco 10000 series that has dual PRE engines that function in ISSU, RPR+, or SSO mode. The symptom may also occur on other platforms that support Enhanced High System Availability (EHSA) such as the Cisco 7304 and Cisco AS5850.
Workaround: There is no workaround.
Further Problem Description: The error message indicates that some of the Entity MIB information such as standby PRE version, standby flash information, and standby EEPROM data has failed to synchronize to the active PRE.
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Symptoms: A Cisco 10000 series with a PRE-3 may crash when you delete an ATM VC.
Conditions: This symptom is observed when the following sequence of events occur:
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Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series may generate an "SW_CORRUPTION" error message when a service of the ISG Layer 4 Redirect feature is removed from a session in a broadband aggregation (BBA) configuration.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an Intelligent Service Gateway (ISG) when a service of the ISG Layer 4 Redirect feature is removed via the configuration of a service policy.
Workaround: There is no workaround.
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Symptoms: A router may reload when you enter the show subscriber session detailed command while sessions are being modified.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Do not enter the show subscriber session detailed command while sessions are being modified.
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Symptoms: When you configure MR-APS between a Cisco 7304 and another router such as a Cisco 7500 series or Cisco 7600 series with PA-MC-STM-1 port adapters, the following tracebacks are logged on the Cisco 7304:
-Process= "APS process", ipl= 0, pid= 191
-Traceback= 406DC2E0 40741174 400C24BC 400C2BF0 400C6D9C 400C79EC 400C8814 400C8894 400C90B8Conditions: This symptom is observed on a Cisco 7304 when the working or protect PA-MC-STM-1 port adapter in the active state.
Workaround: There is no workaround.
Further Problem Description: The symptom occurs with the following Cisco IOS software images:
On the Cisco 7304:
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On the Cisco 7600 series:
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Symptoms: The show atm vc command may be missing VCs.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB or a rebuild of Release 12.2(31)SB when at least one ATM line card is installed and VCs are configured.
Workaround: You can display the ATM VC information by using a more specific command: enter the show atm vc interface atm card/subcard/port command.
Further Problem Description: The missing VCs tend to be from select ATM subinterfaces.
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Symptoms: The PXF engine of an NSE-150 crashes when you enter the ip pim bidir-enable command.
Conditions: This symptom is observed on a Cisco 7304 that is configured for MVPN with a single VRF when multicast traffic is flowing through this VRF.
Workaround: There is no workaround.
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Symptoms: When an ERP timer event occurs for a particular endpoint, the endpoint may become stuck in a continuous loop.
Conditions: This symptom is observed on a Cisco router that is configured for High Availability (HA) In-Service Software Upgrade (ISSU).
Workaround: There is no workaround.
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Symptoms: A "%SYS-2-MALLOCFAIL" error message may be generated, indicating that there is no free memory available in the router.
Conditions: This symptom is observed only on a Cisco 7200 series that is configured with an NPE-G2 and that runs a Cisco IOS software image that is based on Release 12.2S.
Workaround: There is no workaround. To clear the symptom, reboot the router.
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Symptoms: A router crashes when you configure an Xconnect service on a main interface.
Conditions: This symptom is observed on a Cisco router that has two or more L2VPN connections that are configured for Xconnect service on a subinterface of the main interface. Even after you have deleted the subinterface, the router crashes when you configure Xconnect service on the main interface.
Workaround: There is no workaround.
Further Problem Description: This symptom was initially observed on a Cisco 10000 series when you configured Xconnect service on a main interface of a 6-port channelized T3 line card or 4-port channelized STM-1/OC-3 line card. However, the symptom appeared to be platform-independent.
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Symptoms: On a Cisco 7304 that is configured for AToM, a software-forced reload may occur on an NSE-100.
Conditions: This symptom is observed when egress NetFlow is configured on an AToM attachment circuit.
Workaround: There is no workaround.
Further Problem Description: The configuration that is stated in the Conditions is essentially a misconfiguration. NetFlow can collect information only about Layer 3 IP packets. However, the AToM attachment circuit is transmitting Layer 2 frames, so the egress NetFlow is not valid.
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Symptoms: A Cisco 10000 series that has a PRE2 may crash when you clean the configuration via TFTP.
Conditions: This symptom is observed when you first define hierarchical queuing for a QoS VLAN-group policy with a large number of VLAN classes, each class with matching subinterfaces, and then you clean the configuration. The symptom occurs only when you download the configuration via TFTP to the running configuration and when you clean the configuration via TFTP.
Workaround: There is no workaround.
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Symptoms: L2TP connectivity may not function across the native Gigabit Ethernet interface of an NPE-G2.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(31)SB2 when EIGRP is configured as the routing protocol.
Workaround: There is no workaround.
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Symptoms: When an ISG receives VSAs that cannot be parsed by the SIP parser, the ISG disconnects the established session and does not respond with a CoA Nak message.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG when an incorrect VSA is sent via a CoA message and when the SIP parser returns a DENY message to the ISG.
Following are examples of incorrect VSAs:
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cisco-avpair = "atm:vc-weight=3000"–
cisco-avpair = "atm:vc-qos-policy-out=non_exist_policy"
cisco-avpair = "atm:vc-watermark-max=1"Workaround: There is no workaround.
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Symptoms: The usage of the PXF engine increases to 100 percent. This situation may cause interface flapping, error messages that state that OSPF neighbors are unreachable, and a failure of the standby processor.
Conditions: This symptom is observed on a Cisco 7304 that is configured with either an NSE-100 or an NSE-150, that has a POS interface that is configured for Frame Relay and that has an output shaping service policy, and that receives traffic that matches the output shaping service policy. In addition, the router is configured with a cross-connect, more specifically, an interface that is configured for Xconnect service and that is connected to a remote peer.
Workaround: There is no workaround.
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Symptoms: A router that is processing certain MPLS forwarding updates may crash or hang because of a software configuration mismatch.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB but may also occur in other releases. The symptom occurs when EoMPLS or AToM is configured with many virtual circuits (VCs) and when LDP sessions go down because of extreme traffic loads or clearing of the LDP neighbors, causing the forwarding information to be modified.
Workaround: There is no workaround.
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Symptoms: A router may crash when you remove a QoS policy from an interface or modify the policy map.
Conditions: This symptom is observed on a Cisco 7304 that has an NPE-G100 when you configure a QoS policy, attach it to the interface, run traffic, and then, after a long time, remove the QoS policy or modify the policy map.
Workaround: There is no workaround.
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Symptoms: A "%CHKPT-4-INVALID error" error message is generated when you upgrade the Cisco IOS software image to Release 12.2(31)SB.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for ISSU.
Workaround: There is no workaround.
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Symptoms: When the MIB variable tftpHost is empty (that is, it is not defined), you cannot copy an image via ISSU.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB.
Workaround: There is no workaround.
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Symptoms: IS-IS routes are not learned at remote sides.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G2 when the router connects to the remote sides through a native Gigabit Ethernet (GE) interface.
Workaround: Do not use a native GE interface. Rather, use a GE port adapter such as the PA-GE.
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Symptoms: A static Auto-Rendezvous Point (Auto-RP) may not function when both a Frame Relay main interface and one of its subinterfaces have the ip pim sparse-dense mode command enabled.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a PE router in an MVPN network.
Workaround: Remove the ip pim sparse-dense mode command from the main interface but leave the ip pim sparse-dense mode command enable on the subinterface.
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Symptoms: A router may crash when the configured route limit is exceeded. When this situation occurs, the following error message is generated:
%MROUTE-4-ROUTELIMIT (x1): [int] routes exceeded multicast route-limit of [dec] - VRF [chars]Conditions: This symptom is observed on a Cisco 10000 series that is configured for Multicast VPN but is platform-independent.
Workaround: There is no workaround.
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Symptoms: A router crashes when you remove and then add back VRFs.
Conditions: This symptom is observed on a Cisco router that functions as a PE Router in an MPLS VPN network.
Workaround: There is no workaround.
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Symptoms: A memory leak may occur on a router that is configured with IP ACLs.
Conditions: This symptom is observed when you enter the show access-list command to see a list of ACLs that contains dynamic elements.
Workaround: There is no workaround.
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Symptoms: A spurious memory access is generated when you remove the no evaluate tcptraffic command.
Conditions: This symptom is observed on a Cisco router that is configured with IP ACLs.
Workaround: There is no workaround.
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Symptoms: Traffic may no longer be forwarded over a PPPoA session when you remove a policy map from the ATM VC on which the PPPoA session is established.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 when the policy map is applied to the ATM VC and then removed via the no service-policy output policy-map-name command.
Workaround: There is no workaround.
Further Problem Description: With PPPoA (or PPPoEoA), PXF queues are created on the virtual access interface (VAI) even though the policy map is applied to the VC. When the VC policy map is removed, the default PXF queue is also removed from the VAI, causing a traffic black hole.
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Symptoms: A Cisco 10000 series may either fragment or drop an IPv4 packet when the IPv4 packet length is smaller than the configured MTU. Drops may occur when the DF bit is set in the IPv4 header.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB2 when an ARP cache entry times out or when a static ARP entry is deleted from the configuration.
Possible Workaround: Increase the MTU of the interface MTU to mitigate the symptom.
Further Problem Description: The unexpected fragments or packet drops occur in a very short time window after the ARP entry is removed.
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Symptoms: An ISG that receives incorrect VSAs for a policy map may no longer accept any VSAs even if the VSAs are correct.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG and that runs Cisco IOS Release 12.2(28)SB, Release 12.2(31)SB, or Release 12.2(31)SB1.
Workaround: There is no workaround.
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Symptoms: You cannot suppress the creation of F4 OAM VCs when you configure a PVP at the subinterface level. If the PPP client does not support OAM, this situation could prevent the PPP session from being initiated.
Conditions: This symptom is observed on a Cisco router and occurs because there is no no-f4-oam argument available when you configure a PVP on a subinterface.
The following command options are available at the main interface level:
router(config-if)#atm pvp 2 10000 ?
cdvt [Cell Delay Variation Tolerance (CDVT)]
no-f4-mgmt [inhibits the management of f4 oam vcs]
no-f4-oam [inhibits the creation of f4 oam vc's]
crHowever, only the following options are available at the sub interface level:
router(config-if)#atm pvp 2 10000 ?
cdvt [Cell Delay Variation Tolerance (CDVT)]
crWorkaround: Do not configure the PVP on the subinterface. Rather, configure the PVP on the main interface, for which the no-f4-oam argument is available.
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Symptoms: All traffic that arrives on a PPP over VLAN session or PPPoE over QinQ session may be processed indiscriminately by the class default of a service policy that is applied to the VLAN or QinQ VLAN.
Conditions: This symptom is observed on a Cisco 10000 series that runs a Cisco IOS software image that integrates the fix for caveat CSCsg89172. A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsg89172. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: There is no workaround.
TCP/IP Host-Mode Services
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Symptoms: A Cisco router may drop a TCP connection to a remote router.
Conditions: This symptom is observed when an active TCP connection is established and when data is sent by the Cisco router to the remote router at a much faster rate than what the remote router can handle, causing the remote router to advertise a zero window. Subsequently, when the remote router reads the data, the window is re-opened and the new window is advertised. When this situation occurs, and when the Cisco router has saved data to TCP in order to be send to the remote router, the Cisco router may drop the TCP connection.
Workaround: Increase the window size on both ends to alleviate the symptom to a certain extent. On the Cisco router, enter the ip tcp window-size bytes command. When you use a Telnet connection, reduce the screen-length argument in the terminal length screen-length command to 20 or 30 lines.
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Symptoms: A router that is running RCP can be reloaded by a specific packet.
Conditions: This symptom is seen under the following conditions:
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Workaround: Put access lists on the edge of your network blocking RCP packets to prevent spoofed RSH packets. Use another protocol such as SCP. Use VTY ACLs.
Wide-Area Networking
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Symptoms: On a Cisco 7200 series, an error message and traceback such as the following are generated and/or the router may crash because of an "%ALIGN-1-FATAL: Illegal access to a low address" condition:
%SYS-2-BADSHARE: Bad refcount in retparticle, ptr=652AA0C0, count=0 %ALIGN-3-SPURIOUS: Spurious memory access made at 0x621FD418 reading 0x278Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(31)SB when end-to-end Frame Relay fragmentation is configured on an interface.
Workaround: Do not configure end-to-end Frame Relay fragmentation. Rather, configure end-to-end fragmentation that is based on a map class, that is, attach to each PVC a map class that contains an end-to-end fragmentation configuration.
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Symptoms: When you enter the terminate-from hostname host-name command to terminate L2TP tunnels, some L2TP tunnels are terminated in the wrong VPDN group while other L2TP tunnels on the same host are terminated in the correct VPDN group.
Conditions: This symptom is observed on a Cisco 7206VXR that has an NPE-G1 and that runs Cisco IOS Release 12.2SB and occurs only during the first two or three minutes after the router has booted. After that period, the symptom no longer occurs. Note that the symptom is both platform- and release-independent.
Workaround: To prevent the symptom from occurring, enter the no aaa accounting system guarantee-first command on the router before you reload the router. Doing so enables the tunnels to be terminated in the correct VPDN groups.
After the symptom has occurred, clear each of the affected tunnels by entering the clear vpdn tunnel id local-id command. Then, after the tunnels have been re-established, you should be able to terminate them in the correct VPDN groups.
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Symptoms: A router may crash when you configure Frame Relay fragmentation on a Frame Relay main interface after the following error message has been generated:
"Leased-line fragmentation works with main interface service-policy only, please remove policy under subinterface/PVC and re-enter the command."Conditions: This symptom is observed on a Cisco router after you first have attempted to configure Frame Relay fragmentation on a Frame Relay main interface that has a service policy on a subinterface, when you then have removed the service policy from the subinterface, and when you then again attempt to configure Frame Relay fragmentation.
Workaround: After the error message has been generated, immediately remove the Frame Relay fragmentation before you remove the service policy.
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Symptoms: The sessions per-mac throttle command functions as expected, but when you enter the show pppoe throttled mac command, no output is displayed, and a warning message and traceback are generated:
%SYS-2-CHUNKBADMAGIC: Bad magic number in chunk header, chunk 0 data 70A48450 chunkmagic 0 chunk_freema0
-Process= "Exec", ipl= 0, pid= 234
-Traceback= 6053AADC 606167A8 6158DB78 61578A28 61578B4C 604E4BF4 601C01E8
604FE6F8 60617B54 60617B40
604FE6F8 60617B54 60617B40Conditions: This symptom is observed on a Cisco 10000 series that has an PRE-2, that runs Cisco IOS Release 12.2(28)SB4, and that is configured for PPPoE Connection Throttling. Note, however, that the symptom is not platform-specific.
Workaround: There is no workaround.
Open Caveats—Cisco IOS Release 12.2(31)SB2
This section describes possibly unexpected behavior by Cisco IOS Release 12.2(31)SB2. All the caveats listed in this section are open in Cisco IOS Release 12.2(31)SB2. This section describes only severity 1, severity 2, and select severity 3 caveats.
Basic System Services
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Symptoms: A packet of disconnect (POD) does not disconnect a user. When you enable the debug aaa pod command, the output shows the following:
POD: Added Reply Message: No Matching Session
POD: Added NACK Error Cause: Session Context Not FoundConditions: This symptom is observed on a Cisco 10000 series that is configured for AAA when the Account-Session-Id is prepended with information. For example, if the Account-Session-Id is "7/0/0/1.40_00000039" in a POD, the POD fails to find a match.
Workaround: If the Account-Session-Id is "7/0/0/1.40_00000039", configure the POD application to take only the eight right digits: "00000039".
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Symptoms: When a PVC with a policy map is unconfigured on a 1-port OC-12 ATM line card, a Cisco 7304 with an NSE-100 crashes and generates an "ALIGN-1-FATAL" error message.
Conditions: This symptom is observed on a Cisco 7304 that functions as both a core router and a route reflector (RR) when you unconfigure the PVC while traffic is being processed.
Workaround: There is no workaround.
EXEC and Configuration Parser
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Symptoms: When you enter the write memory command, the following error message and a traceback are generated:
Router#wr Building configuration...
% String too long to write to nvram (2578):Compressed configuration from 3452120 bytes to 786685 bytes[OK] Uncompressed configuration from 786685 bytes to 3452120 bytesConditions: This symptom is observed on a Cisco router when the configuration is saved after you have entered the parser config cache interface command.
Workaround: Disable the no parser config cache interface command.
IP Routing Protocols
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Symptoms: CPUHOG messages are generated when the standby RP boots with a very large configuration such as more than 1000 BGP peers.
Conditions: This symptom is observed on a Cisco 10000 series with a PRE-3 when the milliseconds argument of the process-max-time milliseconds command has a value of 50 ms. The symptom is platform-independent.
Workaround: There is no workaround.
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Symptoms: CPUHOG and IPCOIR errors may occur on a Cisco router when you change the IP address of a loopback interface that is associated with a large number of active PPP sessions.
Conditions: This symptom is observed on a Cisco 10000 series that runs slowly when interfaces flap. The symptom is platform-independent.
Workaround: There is no workaround.
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Symptoms: Conflicts may occur between the routes in a BGP table and an IP routing table.
Conditions: This symptom is observed on a Cisco router when BGP routes that are learned via multipaths are reported as locally generated routes (0.0.0.0) in the IP routing table.
Workaround: There is no workaround.
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Symptoms: A router may not resume to forward VPN traffic after you have entered the redundancy force-switchover command.
Conditions: This symptom is observed on a Cisco router that function as a PE router in a VPN environment.
Workaround: There is no workaround.
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Symptoms: A PE router that functions in an MPLS VPN configuration may take a long time to converge.
Conditions: This symptom is observed when an interface goes down and when an MP-BGP next hop that points to this interface is no longer reachable. This MP-BGP next hop remains unreachable until the Interior Gateway Protocol (IGP) finds an alternate path. If the BGP scanner runs while the MP-BGP next hop is unreachable, VRF routes that use this MP-BGP next hop may be removed from the VRF routing table. However, usually, when the next BGP scanner runs, these VRF routes are updated and then re-imported into VRF routing table.
Workaround: The probability for the symptom to occur depends on the elapse time between the interface going down and the IGP convergence and can be decreases by tuning the IGP parameters for a faster convergence.
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Symptoms: Duplicate Interface Index (ifIndex) numbers may be assigned to the multicast tunnel interfaces. This situation may prevent traffic from being switched from these multicast interfaces, and may cause the router to crash with a bus error when these multicast tunnels are deleted and then re-created.
You can verify that the symptom has occurred by entering the show idb command and by looking for duplicate ifIndex entries for the multicast tunnel interfaces.
Conditions: This symptom is observed on a Cisco router that is configured with IPv6 PIM tunnels.
Workaround: There is no workaround.
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Symptoms: The attributes that are configured in a site map may not automatically be applied to the BGP table when the associated interface is running other routing protocols such as RIP or OSPF.
Conditions: This symptom is observed on a Cisco router when routes are redistributed into BGP.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the associated interface.
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Symptoms: Networks do not show in the Multiprotocol BGP (MBGP) table, as can be seen in the output of the show ip mbgp command.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB, Release 12.4, or Release 12.4T.
Workaround: Enter the clear ip bgp neighbor-address command to enable the networks to enter the MBGP table.
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Symptoms: Multiprotocol BGP (mBGP) peers may not receive modified cost-community routes.
Conditions: This symptom is observed on a Cisco router after route maps have been applied. The router checks if the modified routes are sent to its peers. However, the multicast peers do not receive the modified routes.
Workaround: There is no workaround.
Further Problem Description: The routes are sent properly to unicast and VPN peers.
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Symptoms: After a router has booted, BGP links start to flap, and the router crashes.
Conditions: This symptom is observed on a Cisco router that functions as a PE router, that is connected to a route reflector (RR), and that is configured with 500 VRFs and 500 routes per VRF.
Workaround: There is no workaround.
Miscellaneous
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Symptoms: Performance counters under T1.5, T3, and VT2 controllers for T1 and E1 interfaces on a channelized line card are not properly updated and displayed.
Conditions: This symptom is observed on a Cisco 10000 series when cyclic redundancy check (CRC) errors occur.
Workaround: There is no workaround.
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Symptoms: Routed Bridge Encapsulation (RBE) does not function in an IPv6 environment.
Conditions: This symptom is observed on a Cisco router when traffic attempts to pass through an interface that is configured for both RBE and IPv6.
Workaround: There is no workaround.
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Symptoms: Traffic loss may occur for more than 80 seconds after a high availability (HA) switchover has occurred.
Conditions: This symptom is observed on a Cisco 10000 series that has line cards that are configured for Automatic Protection Switching (APS).
Workaround: There is no workaround.
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Symptoms: The output of the show policy-map command may show incorrect WRED counters.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 and that has DSCP-based WRED enabled.
Workaround: There is no workaround.
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Symptoms: When you use the BREAK key to interrupt the image boot process and then enter the dir command from the ROMmon prompt, a recurring "Arithmetic Overflow Exception" may occur.
Conditions: This symptom is observed on a Cisco 10000 series that has 104480 Kbytes of main memory and occurs only when a file system device driver is recursively loaded because you used the BREAK key to interrupt the image boot process and then entered the dir command without first resetting the ROMmon.
Workaround: Let the image boot and then enter the dir command. If you must interact with the file system via the ROMmon when the boot process has been interrupted, enter the reset command. If autoboot is enabled, use the BREAK key immediately after the banner line appears on screen.
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Symptoms: A router may crash when you configure Mobile IP.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.12SB or Release 12.2SBC.
Workaround: There is no workaround.
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Symptoms: The following symptoms may occur:
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Conditions: This symptom is observed when multicast fast switching is configured over mGRE tunnels.
Workaround: There is no workaround.
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Symptoms: The statistic counters for a parent policy and for parts of a child policy may be incorrect in the output of the show policy-map interface interface-name command.
Conditions: This symptom is observed on a Cisco 10000 series when an egress policy map is attached to an interface, when the egress policy map has a nested child service policy, and when you modify class maps in the child policy.
Workaround: Remove the child policy map from the parent policy map before you modify the child class maps. Then, re-attach the child policy to the parent.
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Symptoms: When more than 100 pseudowire (PW) VCs are brought down simultaneously, enqueue failures occur, preventing PWE3-MIB notifications from being sent for the PW VCs beyond the first 100 PW VCs that went down.
Conditions: This symptom is observed on a Cisco 10000 series and occurs because the notification queue of the PWE3-MIB is full.
Workaround: Configure a network management station (NMS) to report that a state change occurs for PW VCs, for example, via the MPLS-LDP-MIB.
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Symptoms: A Cisco 10000 series may reload unexpectedly during HA configuration synchronization operations.
Conditions: This symptom is observed very rarely on a Cisco 10000 series that runs Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series that has a scaled configuration may crash when an SSO switchover occurs.
Conditions: This symptom is observed on a Cisco 10000 series that functions in the following large Remote Access (RA) to MPLS VPN configuration:
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Workaround: There is no workaround.
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Symptoms: Packet loss may occur on voice or video streams when you apply an output policy on the interface.
Conditions: This symptom is observed on a Cisco 10000 series when traffic is sent at line rate.
Workaround: There is no workaround.
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Symptoms: When Internet mix (IMIX) traffic is processed over an L2VPN pseudowire that is configured for shaping on a disposition PE router, shaping does not function as expected, causing packets to be dropped.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a disposition PE router.
Workaround: There is no workaround.
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Symptoms: The maximum latency of priority queueing (PQ) may be too high for some ports.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: The on-demand address pool (ODAP) manager does not create the required number of subnets.
Conditions: This symptom is observed on a Cisco router that has the DHCP ODAP Server Support feature enabled.
Workaround: There is no workaround.
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Symptoms: The running configuration may not be accessible after you have copied a small file to the running configuration.
Conditions: This symptom is observed on a Cisco router that has an ATA file system after you have rebooted the router.
Workaround: Reboot the router once more.
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Symptoms: When an interface is configured for Routed Bridge Encapsulation (RBE) and Dynamic Host Control Protocol (DHCP) and when an HA switchover occurs, routes do not synchronize on the new standby RP.
Conditions: This symptom is observed on a Cisco 10000 series after you have performed an OIR of the interface that is configured for RBE and DHCP. The symptom may be platform-independent.
Workaround: There is no workaround.
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Symptoms: An MPLS tunnel goes down after you have changed the tunnel priority from 3 to 2 via the tunnel mpls traffic-eng priority command.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: A standby RP may reload repeatedly when you enter the issu loadversion command during a period of high checkpointing activity. When you enter the show checkpoint statistics command on the active RP, the output shows that the checkpointing IPC flow control status remains set to zero indefinitely:
CHKPT FLOW_ON status = 0Conditions: This symptom is observed on a Cisco router when the standby RP reloads as part of the In-Service Software Upgrade (ISSU) process while, for example, a large number of PPPoA sessions are being disconnected.
Workaround: There is no workaround to prevent the symptom from occurring. When the symptom has occurred, enter the issu abortversion command to cancel the ISSU process, and then reload the router.
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Symptoms: A router crashes when you unconfigure and then reconfigure MLPoFR.
Conditions: This symptom is observed on a Cisco router that has a QoS service policy with traffic shaping.
Workaround: There is no workaround.
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Symptoms: When Multilink PPP (MLP) is configured to use a virtual access interface as the bundle interface and when you apply a service policy with bandwidth guarantees that are higher than the bandwidth guarantees of the virtual access interface, an error message is generated because the service policy is not rejected nor enters the suspended mode.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB and that is configured for MLP and QoS.
Workaround: Add more links to the bundle interface and clear the virtual access interface.
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Symptoms: Memory failures may occur on a Cisco 10000 series when you repeatedly perform OIRs.
Conditions: This symptom is observed very rarely on a Cisco 10000 series that runs Cisco IOS Release 12.2SB after repeated OIRs of a line card that is configured for Auto VCs and that has active PPPoA sessions.
Workaround: There is no workaround.
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Symptoms: cRTP may become disabled on an interface when you disable and re-enable the ip rtp header-compression command on the interface.
Conditions: This symptom is observed on a Cisco router that functions in an MLP configuration when the link (such as a Frame Relay link) and the MLP bundle clone from the same virtual template.
Workaround: Reset the interface.
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Symptoms: When you repeatedly clear PPPoA sessions, memory may become fragmented, and eventually may become so low and fragmented that you cannot execute the show running-config command.
Conditions: This symptom is observed on a Cisco 10000 series when you repeatedly clear PPPoA PTA sessions by entering the clear pppatm command.
Workaround: There is no workaround.
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Symptoms: Spurious memory accesses may occur on a Cisco 10000 series that is configured for PPPoA.
Conditions: This symptom is observed when you first add and then remove Variable Bit Rate (VBR) from a VC class for active PPPoA sessions.
Workaround: There is no workaround.
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Symptoms: The police counters are not properly incremented after a class has been added or deleted.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(31)SB2 when the total number of classes crosses a power-of-2 boundary after a class has been added to or deleted from the policy that is attached to an interface.
For example, the symptom occurs under the following conditions:
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Workaround: Detach the service policy from the interface, add or delete a class to or from the policy, and re-attach the policy.
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Symptoms: When you configure an ATM VC on which PPPoE sessions are established, a spurious memory access may be generated.
Conditions: This symptom is observed on a Cisco router when the VC is torn down.
Workaround: There is no workaround.
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Symptoms: The number of BECN-tagged packets that are sent by one CE router does not match the number of BECN-tagged packets that are received by another CE router. This symptom can be verified in the output of the show frame-relay pvc command.
Conditions: This symptom is observed under the following conditions:
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Workaround: There is no workaround.
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Symptoms: QoS statistics are not reflected properly in the output of the show policy-map session uid uid-number command.
Conditions: This Symptom is observed on a Cisco 10000 series is has a PRE2 and that functions as a LAC.
Workaround: There is no workaround.
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Symptoms: A router crashes when a non-VLAN user class is configured under a parent policy with an action such as the set qos-group command.
Conditions: This symptom is observed on a Cisco 10000 series and occurs because a non-VLAN user class under a parent policy is an illegal configuration.
Workaround: Do not configure a non-VLAN user class under a parent policy. However, note that you can configure a VLAN user class under a parent policy.
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Symptoms: I/O memory may become depleted on a Cisco 7304 because of IPC buffer usage. This situation may also cause the following error messages to be generated:
%WSIPC-3-SYSCALL: System call for command 7 (port 4/1): ipc_send_rpc_blocked timed-out (Cause: timeout)
-Traceback= 406EB43C 40924448 409245FC 40924750Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 and three Port Adapter Carrier Cards (7300-CC-PAs) in which 8-port serial, X.21 port adapters (PA-8T-X21) are installed and occurs when many serial interfaces are reset.
Workaround: Prevent the serial interfaces from being reset.
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Symptoms: A standby RP may continuously reload after you have entered the redundancy force-switchover command.
Conditions: This symptom is observed on a Cisco router that has the atm pvp vpi l2transport interface configuration command enabled for an AToM tunnel that functions in ATM PVP mode.
Workaround: Disable the atm pvp vpi l2transport interface configuration command. When you do so, the standby RP comes back up.
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Symptoms: When a failure occurs on a CE router, the primary pseudowire switches over to the backup pseudowire. However, when the failure is corrected, the backup pseudowire does not fall back to the primary pseudowire but remains in the "UP" state.
Conditions: This symptom is observed on a Cisco router that functions as a CE router when the ATM-to-ATM Local Switching and L2VPN Pseudowire Redundancy features are configured with an AToM (like-to-like) pseudowire class. The symptom occurs only in an ATM configuration.
Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface that faces the PE router. Doing so forces the primary pseudowire to come up.
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Symptoms: The call setup rate on an LNS may be very slow.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an LNS.
Workaround: There is no workaround.
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Symptoms: A CPUHOG condition may cause an interface of an OC-12 port line card to flap even though the remote link is still active.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: All ingress traffic into a Gigabit Ethernet (GE) SPA may be ignored.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 or NSE-150 when the following conditions are present:
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You must reload the router to recover proper functionality.
Workaround: Enable PXF.
Alternate Workaround: Do not perform a series of consecutive physical OIRs of the MSC-100 while traffic is being switched and the CPU usage of the NSE is at 99 or 100 percent.
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Symptoms: A policing error may occur on a DHCP IP session when local authorization is configured.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Configure a static IP session and RADIUS authorization.
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Symptoms: The CPU of a router may spike when an empty control policy is configured on an interface and when another non-empty control policy is configured at either the global or the interface level.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Do not configure an empty control policy on the interface.
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Symptoms: When you change the MTU on a virtual template, an incorrect value is used for the IP MTU.
Conditions: This symptom is observed when the value that is set as the MTU via the mtu bytes command is automatically entered as the maximum value for bytes argument of the ip mtu bytes command.
This symptom occurs only with MTU values in the range of 64 to 67 when an IP MTU is also configured. MTU values from 68 up to the interface maximum work fine. Some interfaces allow a minimum MTU value of 64 but the minimum IP MTU value is 68, therefore, MTU values in the range of 64 to 67 may cause a problem.
For example, when you change the MTU via the mtu bytes command to a minimum value of 64 while the IP MTU has a minimum value of 68, the IP MTU is automatically changed to a maximum value of 64, which causes the IP MTU to cover an incorrect range.
Workaround: Avoid MTU values in the range from 64 to 67.
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Symptoms: CEF convergence takes a long time in a load-balancing configuration on a Cisco 10000 series that has a PRE-3.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a PE router in an MPLS VPN configuration and that is connected to two P routers. The symptom occurs after an interface has flapped.
Workaround: There is no workaround.
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Symptoms: When you configure the C2 overhead byte under SONET T3 or VT controllers on a 1-port channelized OC-12/STM-4 or 4-port channelized STM-1/OC-3 line card, the T3 or VT controllers may not come up.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: DHCP control messages that are sent by a DHCP relay agent and that are destined for an external DHCP server do not pass through an interface of an Intelligent Service Gateway (ISG).
Conditions: This symptom is observed on a Cisco router that functions as an ISG when the interface is configured for IP Session Creation.
Workaround: There is no workaround.
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Symptoms: Multilink PPP (MLP) traffic fails when it is forwarded via a LAC (or LNS) over an PPPoA session.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a LAC and that runs Cisco IOS Release 12.2(28)SB2. The symptom occurs when the MLP traffic comes from an ADSL router via an L2TP session and when the CPE connects to the LAC via PPPoA.
Workaround: Configure the CPE to connect to the LAC via PPPoEoA instead of PPPoA.
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Symptoms: When traffic is being processed at a low speed such as 56 Kbps, intermittently, traffic comes to a complete halt on a Frame Relay subinterface.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2. The symptom occurs when the PXF engine stops dequeueing packets on the Frame Relay subinterface, causing the interface output queue to become wedged.
Workaround: Remove the service policy from the subinterface and then re-apply the service policy to the subinterface.
Further Problem Description: Without applying the workaround, about 60 to 70 minutes after the output queue has become wedged, the output queue starts to dequeue itself.
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Symptoms: When an unknown Change of Authorization (CoA) service policy is pushed to an active ISG session, the service policy is not acknowledged and the ISG session is terminated.
Conditions: This symptom is observed on a Cisco router that functions as an ISG. The following is an example of the conditions under which the symptom occurs:
A CoA service policy is pushed in the following VSA format:
vsa cisco generic 1 string "subscriber:policy-directive=service-policy type service name BOOTONE"The BOOTONE service does not exist in the local ISG profile database, nor in the AAA service database.
Workaround: There is no workaround.
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Symptoms: When you enter the clear ip dhcp binding command to clear DHCP bindings, the corresponding DHCP-initiated subscriber sessions are not cleared.
Conditions: This symptoms is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Enter the clear ip subscriber command to clear the subscriber sessions.
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Symptoms: When traffic is processed over a session after you have removed the standby RP, a memory leak may occur in the an "adj_allocate_setup_and_lock" process.
Conditions: This symptom is observed on a Cisco router that is configured for PTA and L2TP sessions.
Workaround: Do not remove the standby RP after you have booted the router.
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Symptoms: A multicast ping packet that is sent from one CE router to another CE router may be dropped.
Conditions: This symptom is observed on a Cisco 7304 and Cisco 10000 series that function in a Multicast VPN (MVPN) configuration with Autonomous System Border Routers (ASBRs).
Workaround: There is no workaround.
Further Problem Description: The symptom does not occur on a Cisco 7200 series.
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Symptoms: A router may be unable to bring up more than 36,000 sessions in a configuration with VC-classes and QoS policy maps. Memory errors may be reported and sessions may be disconnected.
Conditions: This symptom is observed on a Cisco router that functions as an ISG and occurs only when all of the following criteria are present:
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Workaround: There is no workaround.
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Symptoms: The cache entries of Flexible NetFlow may lock up for multicast traffic.
Conditions: This symptom is observed during normal Flexible NetFlow operation when multicast traffic enters the router.
Workaround: There is no workaround.
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Symptoms: Duplication or tapping does not occur on a Cisco 7301 that is configured for Lawful Intercept (LI).
Conditions: This symptom is observed when a PPPoE session is set up at the client and when you attempt to duplicate packets at a Cisco 7301 that functions as a LAC and that is configured for LI. The symptom is platform-independent.
Workaround: There is no workaround.
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Symptoms: The working interface is not restored to the active state but remains inactive while the protect interface remains active in the following situation:
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The working interface should become active but does not do so.
Conditions: This symptom is observed on a Cisco 7304 when interfaces of an OC-3 POS line card are configured for APS and occurs only in a back-to-back bi-directional APS configuration. The symptom does not occur with an OC-3 POS port adapter.
Workaround: Perform a soft OIR of the working interface.
Alternate Workaround: Disable the pos ais-shut command on the working interface.
Possible Workaround: Enter the pos scramble-atm on the active interface. Note that this workaround does not always work.
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Symptoms: When dynamic bandwidth selection (DBS) is enabled on an ATM VC, policing on PPPoX sessions may exceed the configured policing rates.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an Intelligent Service Gateway (ISG) when the following sequence of events occurs:
1.
2.
3.
After you have torn down the second session, traffic flowing through the first session may exceed the policing values that have been configured.
Workaround: Disable DBS on the interface on which the ATM VC is configured.
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Symptoms: Incorrect police percent conversions occur in the second and third levels of a policy.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2SB. However, the symptom is platform-independent.
Workaround: There is no workaround.
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Symptoms: A Cisco 7206VXR crashes because of a software bus error when the main interface is shut down and brought up again.
Conditions: This symptom is observed on a Cisco 7206VXR with an NPE-G1 that runs Cisco IOS Release 12.2(28)SB5 and that has a Frame Relay map class with a QoS service policy that is applied to an MFR subinterface.
Workaround: Remove the Frame Relay map class from the MFR subinterface.
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Symptoms: The PXF engine on an NSE-150 may crash at PXF column 2 when a switchover occurs while traffic is being processed. When this situation occurs, no information is written to the crashinfo file.
Conditions: This symptom is observed on a Cisco 7304 that is configured for HA, that has 250 FEC VRFs, and that has the ip cef and ip pxf commands enabled.
Workaround: Do not enable the ip cef command in an HA configuration. Rather, enable the ip cef distributed command.
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Symptoms: The following error message is generated when a PVC is shut down.
%ATM-3-FAILMODIFY VC: failed to modify messages in the logConditions: This symptom is observed on a Cisco 10008 when a PVC is shut on the remote side.
Workaround: There is no workaround.
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Symptoms: A router may crash when a policy map that is in use by sessions is modified while the sessions are disconnected.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 but may not be limited to this platform.
Possible Workaround: Clear all sessions before you modify the policy map.
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Symptoms: A DHCP-initiated IP subscriber session may not respond to DHCP control packets.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG) when the subscriber session has features enabled that affect the handling of the DHCP control packets.
Workaround: Apply access control lists (ACLs) to the subscriber session to permit bidirectional DHCP control traffic between the ISG and the DHCP client. To do so, enter the access-list access-list-number permit udp any any eq bootps command.
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Symptoms: The PA-CC on a Cisco 7304 that has an NSE-100 may crash when you enter the clear interface atm command more than once for the interface of a 1-port ATM OC-3c/STM-1 multimode, enhanced port adapter (PA-A6-OC3MM) that is installed in the PA-CC.
Conditions: This symptom is observed on a Cisco 7304 when the PA-A6-OC3MM is configured with 500 VRFs, when traffic is passing through all the VRFs, and when not all VCs have come up after the previous clear interface atm command was entered while you enter the clear interface atm command again.
Workaround: After you have entered the clear interface atm command, wait for all the VCs to come up before you enter the clear interface atm command again.
Alternate Workaround: Do not enter the clear interface atm command. Rather, enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface of the PA-A6-OC3MM.
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Symptoms: A Gigabit Ethernet connection between a Gigabit Ethernet port on a Cisco 10000 series and another platform may become inoperative unexpectedly.
Conditions: This symptom is observed randomly on a Cisco 10000 series that runs Cisco IOS Release 12.2SB and that has an interface that is configured for auto-negotiation on a full-height or half-height Gigabit Ethernet line card.
Possible Workarounds: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the affected interface. If this workaround does not clear the symptoms, enter the hw-module reset command for the affected line card. If neither of these workarounds clear the symptoms, reload the router.
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Symptoms: An invalid traceback address may be displayed as part of a CPUHOG error message, as in the following example:
%SYS-3-CPUHOG: Task is running for (2000)msecs, more than (2000)msecs (6/6),process = Virtual Exec. -Traceback= BFC30E70Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 and that runs Cisco IOS Release 12.2(31)SB2 when commands are entered from the virtual terminal.
Workaround: There is no workaround.
Further Problem Description: When the symptom occurs, collect the output of the show processes cpu sorted | ex 0.00 command. Then, for the processes that have a high CPU usage as shown in the output of the show processes cpu sorted | ex 0.00 command, enter the show stack # command and substitute the PID of the output of the show processes cpu sorted | ex 0.00 command for the # argument in the show stack # command. Then, submit all output to the Cisco Technical Assistance Center (TAC) for further assistance.
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Symptoms: An OC-3 POS interface on a Cisco 10000 series that is connected to a Cisco 7200 series remains in the down/down state after you have entered the shutdown interface configuration command followed by the no shutdown interface configuration command on the OC-3 POS interface.
Conditions: This symptom is observed on a Cisco 10000 series that has a 6-port OC-3 POS line card.
Workaround: Reload the Cisco 10000 series.
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Symptoms: CPU usage may be at 100 percent for more than 10 minutes, and all line cards may reboot.
Conditions: These symptoms are observed very rarely on a Cisco 10000 series when a large number of links on the router flap while traffic is being processed.
Workaround: There is workaround.
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Symptoms: A Cisco 10000 series that is configured for PPP may crash because of memory corruption.
Conditions: This symptom is observed rarely on a Cisco 10000 series when a large number of serial links flaps during a long period of time, causing multilink bundles to go up and down.
Workaround: There is no workaround.
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Symptoms: Traffic is lost for 10 to 15 seconds after a PRE switchover has occurred.
Conditions: This symptom is observed on a Cisco 10000 series immediately after the standby PRE enters the hot standby state.
Workaround: There is no workaround.
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Symptoms: When you configure a traffic class to classify traffic on precedence 2 with a mark probability denominator of 1/5 and on precedence 6 with a mark probability denominator of 1/10, the output of the show policy-map interface command shows that the mark probability denominator for both precedence values is 1/10.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(28)SB2 and that is configured for WRED.
Workaround: There is no workaround.
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Symptoms: When a microcode reload is performed, the router may crash and generate the following error message:
%ERR-1-GT64120 (PCI-1): Fatal error, PCI Master abortConditions: This symptom is observed on a Cisco 10000 series when you enter the microcode reload all command.
Workaround: There is no workaround.
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Symptoms: A Port Adapter Carrier Card (CC-PA) on a Cisco 7304 may crash and generate the following error messages and tracebacks in the logs:
%WSIPC-3-SYSCALL: System call for command 7 (port 2/0) : ipc_s end_rpc_blocked timed-out (Cause: timeout)
-Traceback= 406F016C 40929BC4 40929D78 40929ECC
%LC-3-RECOVERY: Line card (slot 2) recovery in progress
-Traceback= 406F016C 408B9028 401F3680 408C017C 4087FAE4 408645E4 407F1E64
%LC-3-SANTAANA: Santa Ana Asic: NSE instance 0, Serial Channel A (slot 2), Error Status 0x9 Detected padding
%LC-3-SANTAANA: Santa Ana Asic: Line card instance 0, Serial Channel A (slot 2), Error Status 0x0
%LC-3-IOTIMEOUT: RP CI-MUX FPGA read timeout (Slot 2, Serial Channel 0)Conditions: This symptom is observed once every 20 hours on a Cisco 7304 that has a CC-PA that runs firmware revision 1.40.
Workaround: There is no workaround.
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Symptoms: A 4-port OC-3 ATM line card (ESR-4OC3-ATM) may not restart properly on a Cisco 10000 series that has a PRE-2.
Conditions: This symptom is observed only when the router boots while the MTU of the interface on the ESR-4OC3-ATM is different from the default MTU. The symptom does not occur if you change the default MTU of the interface after the router has booted.
Workaround: Disable the mtu bytes interface configuration command and restart the ESR-4OC3-ATM.
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Symptoms: During dynamic VLAN class modifications, the queueing policy inheritance fails. This situation causes traffic to be dropped.
Conditions: This symptom is observed on a Cisco 10000 series that has a hierarchical queueing policy for VLAN classes and a flat shape for the class default. When the VLAN class modifications occur that shift the matching subinterfaces to the class default, then back to the original VLAN class, and then to another VLAN class, the child queues are not created, causing traffic to drop.
Workaround: Remove and re-attach the hierarchical queueing policy.
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Symptoms: Non-Priority Queuing (PQ) traffic in a class default in a QoS policy that includes the match vlan command is not dequeued during oversubscription of the PQ class.
Conditions: This symptom is observed on a Cisco 10000 series only when there are multiple VLAN classes and when there are child queueing policies in the class default and the VLAN classes. The PQ policer takes the interface bandwidth as reference, causing policing to occur at the wrong rates and starvation of non-PQ child classes in the class default. The symptom does not occur for child classes in a VLAN class.
Workaround: There is no workaround.
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Symptoms: Traffic stops matching to a child policy.
Conditions: This symptom is observed on a Cisco 10000 series when an interface has a hierarchical policy defined on a PVC, when you remove the child policy, and when you re-attach the child policy to the parent policy of the hierarchical policy. In this situation, the traffic no longer matches to the child policy.
Workaround: Detach the hierarchical policy from the PVC, modify the child policy, and re-attach the hierarchical policy to the PVC.
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Symptoms: T1 interfaces flap intermittently, causing input, CRC, frame, and abort errors to be generated.
Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2(28)SB4.
Workaround: There is no workaround.
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Symptoms: Temperature alarms on a Cisco 10000 series PRE-3 assert at lower ambient temperatures than necessary.
Conditions: This symptom may occur in an operating environment in which the ambient temperature is in the low 30s (degrees Celsius).
Workaround: You can reprogram the temperature alarm thresholds. The recommended thresholds are:
inlet minor: 41 C
inlet major: 51 C
inlet critical: 73 C
outlet minor: 48 C
outlet major: 58 C
outlet critical: 85 C•
Symptoms: When a client attempts to establish an IP session by using an IP assignment from the DHCP server of an Intelligent Service Gateway (ISG), the IP session may not be established.
Conditions: This symptom is observed on a Cisco router that functions as an ISG when the following conditions are present:
–
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Workaround: In addition to or instead of the initiator unclassified mac-address or initiator unclassified ip command, enter the initiator dhcp class-aware command on the client-facing interface.
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Symptoms: When the standby PRE comes up, the following error message is generated on the console of the active PRE:
REDUNDANCY-3-IPC: cannot open standby port session in useConditions: This symptom is observed on a Cisco 10000 series that has dual PRE engines that function in ISSU, RPR+, or SSO mode.
Workaround: There is no workaround.
Further Problem Description: The error message indicates that some of the Entity MIB information such as standby PRE version, standby flash information, and standby EEPROM data has failed to synchronize to the active PRE.
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Symptoms: When you enter the clear counters command, a Cisco 7304 that has an NSE-150 may crash and generate a TLB exception.
Conditions: This symptom is observed when the Cisco 7304 is configured with 500 VRFs on an PA-A6 port adapter, when 250 VRFs are active, and when you perform a soft OIR for the PA-A6 and then enter the clear counters command.
Workaround: There is no workaround.
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Symptoms: A counter may indicate double values and packets are punted from the PXF engine to the RP and then dropped.
Conditions: This symptom is observed on a Cisco 7304 when you apply an ACL deny statement on the egress interface.
Workaround: There is no workaround.
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Symptoms: Traffic loss, framing errors, CRC errors, input errors, and abort errors may occur on DS1 interfaces after an APS switchover occurs because a line card has reset.
Conditions: This symptom is observed on the Cisco 10000 series that has a 1-port channelized OC-12 line card that is configured for channelized T3 traffic and MR-APS. The framing, CRC, input, and abort errors may occur even when traffic is not flowing.
Workaround: There is no workaround.
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Symptoms: The PXF engine of a Cisco 10000 series may crash.
Conditions: This symptom is observed rarely on a Cisco 10000 series when MLP is configured and when member links flap frequently.
Workaround: There is no workaround.
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Symptoms: After you have reloaded a router, VRF routes disappear.
Conditions: This symptom is observed when you reload a router the processes a heavy traffic flow.
Workaround: Enter the clear ip route vrf vrf-name command.
Alternate Workaround: Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the interface from which the VRF routes have disappeared.
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Symptoms: A router that has an hierarchical policy on an ATM VC may reload unexpectedly.
Conditions: This symptom is observed on a Cisco 7206VXR that is configured with an NPE-G1 but may be platform-independent.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series may generate a "SW_CORRUPTION" error message when a service of the ISG Layer 4 Redirect feature is removed from a session in a broadband aggregation (BBA) configuration.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an Intelligent Service Gateway (ISG) when a service of the ISG Layer 4 Redirect feature is removed via the configuration of a service policy.
Workaround: There is no workaround.
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Symptoms: After you have deleted a VLAN class from a bi-level policer policy in the ingress direction, class-default traffic is not aggregately policed by the parent policer that is defined for the default class.
Conditions: This symptom is observed on a Cisco 10000 series that has a VLAN class with a child policer policy and a class default also with a child policy when you first attach the policy to an interface and then delete the VLAN class from the policy.
Workaround: There is no workaround.
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Symptoms: The PXF engine of a Cisco 10000 series may crash.
Conditions: This symptom is observed rarely on a Cisco 10000 series when MLP is configured and when member links flap frequently.
Workaround: There is no workaround.
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Symptoms: A router may crash when you attach a Frame Relay map class to a subinterface that has already a map class attached or when you remove the DLCI from a Frame Relay subinterface that still has a map class attached.
Conditions: These symptoms are observed on a Cisco 7200 series.
Workaround: Remove the existing map class from the subinterface before you attach a new map class or remove the DLCI.
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Symptoms: The aggregate values of the scheduler may be incorrectly updated for high-speed links. This situation may cause delay before policy maps take effect.
Conditions: This symptom is observed on a Cisco 10000 series under rare circumstances with high-speed links such as 100 Mbps and Gigabit Ethernet links for which a parent shaper is configured.
Workaround: There is no workaround.
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Symptoms: Traffic drops occur when packets with a size of 64 bytes are being processed.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2.
Workaround: There is no workaround.
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Symptoms: When a line card failover occurs on a router that has redundant 4-port channelized T3 half-height line cards (ESR-HH-4CT3 line cards), the following error message and a traceback may be generated:
%C10KHHCT3-4-LINECARDFAILOVER: LC Y-Cable cutover from subslot 4/1 due to freedm xmt partial packet fifo underrun errorConditions: This symptom is observed on a Cisco 10000 series that is configured for failover protection through Y-cables when you initiate a line card failover by entering the shutdown interface configuration command followed by the no shutdown interface configuration command on one of the ESR-HH-4CT3 line cards or by entering the hw-module subslot slot-number/subslot-number reset command for one of the ESR-HH-4CT3 line cards.
Workaround: There is no workaround.
Further Problem Description: Because of this caveat, the "xmt partial packet error" indication is currently not enabled to initiate an automatic line card failover on a router with redundant ESR-HH-4CT3 line cards. The error message is currently for information only.
By nature, a line card failover may produce erroneous error indications on the line card. Further investigations have lead to the belief that the line card software is reading invalid error register information just after a failover occurs, producing an erroneous error message. Error indication registers should be cleared by the line card software following any line card failover before reading these registers again for valid error indications.
When this caveats is resolved, the "xmt partial packet error" indication will be enabled as one of the mechanisms for an automatic line card failover.
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Symptoms: When a policy map is unconfigured from a Fast EtherChannel (FEC) interface, a Cisco 7304 may crash and generate an "ALIGN-1-FATAL" error message without a traceback.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 and that is configured with 250 VRFs on the FEC interface. In addition, the Cisco 7304 is configured with 250 Frame Relay links and 250 dot1q VRFs. The symptom occurs while traffic is flowing through the FEC interface.
Workaround: There is no workaround.
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Symptoms: A router may crash when the execution of the show policy-map command is at the -More- prompt via one connection while the policy map is being modified or deleted via another connection.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-3 but may not be limited to this platform.
Workaround: There is no workaround.
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Symptoms: A ping between a CE router that is configured for ATM and another CE router that is configured for Ethernet may fail over an AToM tunnel when the interworking ethernet command is enabled on a connected PE router.
Conditions: This symptom is observed on a Cisco 7200 series that functions as a PE router and may occur because of a timing issue. The symptom may not be platform-specific.
Workaround: Do not enter the interworking ethernet command on the PE router. Rather, enter the interworking ip command.
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Symptoms: When you first remove the encapsulation frame-relay command from a serial interface and then attempt to copy the startup configuration to the running configuration, a Cisco 7304 may crash and generate the following error message:
Data Bus Error exception, CPU signal 10, PC = 0x40A24800.Conditions: This symptom is observed on a Cisco 7304 with an NSE-100 that has 250 Frame Relay, 250 Fast EtherChannel, and 250 dot1q VRFs while traffic is flowing through all these VRFs. QoS is configured on the core-facing interfaces of the Cisco 7304 and on the connected PE routers.
Workaround: There is no workaround.
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Symptoms: A router may reload when you enter the show subscriber session detailed command while sessions are being modified.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG).
Workaround: Do not enter the show subscriber session detailed command while sessions are being modified.
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Symptoms: On a Cisco 7200 series with an NPE-G1, channelized T3 links may flap. On a Cisco 7200 series with an NPE-G2, the serial interface may become wedged without the interface output queue being full.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(31)SB2 and that is configured with a 2-port multichannel T3 port adapter (PA-MC-2T3+).
Workaround: There is no workaround.
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Symptoms: The show atm vc command may be missing VCs.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB or a rebuild of Release 12.2(31)SB when at least one ATM line card is installed and VCs are configured.
Workaround: You can display the ATM VC information by using a more specific command: enter the show atm vc interface atm card/subcard/port command.
Further Problem Description: The missing VCs tend to be from select ATM subinterfaces.
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Symptoms: A router may crash when you configure it with a high number of PPP over Ethernet over VLAN (PPPoEoVLAN) sessions that are spread over hundreds of VLAN subinterfaces.
Conditions: This symptom is observed on a Cisco 10000 series that has a PRE-2 or PRE-3.
Workaround: There is no workaround.
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Symptoms: L2TP connectivity may not function across the native Gigabit Ethernet interface of an NPE-G2.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2(31)SB2 when EIGRP is configured as the routing protocol.
Workaround: There is no workaround.
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Symptoms: A router that is processing certain MPLS forwarding updates may crash or hang because of a software configuration mismatch.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(31)SB but may also occur in other releases. The symptom occurs when EoMPLS or AToM is configured with many virtual circuits (VCs) and when LDP sessions go down because of extreme traffic loads or clearing of the LDP neighbors, causing the forwarding information to be modified.
Workaround: There is no workaround.
TCP/IP Host-Mode Services
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Symptoms: BGP sessions that are established between two route reflectors (RRs) flap continuously because TCP times out for keepalives.
Conditions: This symptom is observed on a Cisco router that functions as an RR in an MPLS VPN Interautonomous System (InterAS) scenario and occurs when the RR receives VPNv4 prefixes from a PE router. In this situation, the BGP session between the RR and the second RR flaps.
Workaround: There is no workaround.
Wide-Area Networking
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Symptoms: When you add Variable Bit Rate (VBR) traffic shaping parameters to active PPPoA sessions, a Cisco 10000 series may crash and generate the following error message:
%ERR-1-GT64120 (PCI-1)Conditions: This symptom is observed when PPPoA sessions without VBR are in the process of coming up while you add VBR traffic shaping parameters.
Workaround: Wait until the sessions are completely up and then add VBR traffic shaping parameters.
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Symptoms: A Cisco 10000 series may run out of memory after a number of ATM port flaps have occurred.
Conditions: This symptom is observed on a Cisco 10000 series that is configured with 28,000 PPPoA Point-to-Point Termination and Aggregation (PTA) sessions. Each time that the ATM ports that carry the sessions flap and in this process remain down long enough for the sessions to time-out, more memory is lost.
Workaround: There is no workaround.
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Symptoms: A router may exhaust its I/O memory.
Conditions: This symptom is observed on a Cisco router when you clear 10,000 tunnels on which about 45,000 PPP sessions are established. The symptom occurs only under extreme stress situations.
Workaround: Clear the tunnels and sessions in stages.
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Symptoms: PPP packets are dropped and the Network Control Programs (NCPs) are not negotiated.
Conditions: This symptom is observed when you force a DHCP renewal of a lease for a DHCP client on a virtual-template interface.
Workaround: Delete and reconfigure the virtual-template interface.
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Symptoms: A Cisco router crashes when you enter the compress predictor command to configure Predictor software compression.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100. However, the symptom is platform-independent.
Workaround: There is no workaround.
Further Problem Description: The symptom does not occur for Limpel Zif Stac (LZS) software compression.
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Symptoms: When PPPoE Relay is configured, only one session comes up successfully. All successive sessions fail. The initiation of more sessions brings down the existing sessions. If there are active sessions that are already existing (not necessarily PPPoE Relay sessions), the initiation of new PPPoE Relay sessions tears down all the sessions.
Conditions: These symptoms are observed on a Cisco router that functions in a Virtual Private Dialup Network (VPDN). The symptom occurs only for PPPoE Relay sessions and not for normal sessions.
Workaround: There is no workaround.
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Symptoms: A router that functions as an L2TP LNS for remote-end customer PCs that function as LACs crashes during normal operation.
Conditions: This symptom is observed on a Cisco router that functions as a LNS in a Virtual Private Dialup Network (VPDN) and that runs Cisco IOS Release 12.2(28)SB2 or Release 12.4(8).
Workaround: There is no workaround.
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Symptoms: When you enter terminate-from hostname host-name command to terminate L2TP tunnels, some L2TP tunnels are terminated in the wrong VPDN group while other L2TP tunnels on the same host are terminated in the correct VPDN group.
Conditions: This symptom is observed on a Cisco 7206VXR that has an NPE-G1 and that runs Cisco IOS Release 12.2SB and occurs only during the first two or three minutes after the router has booted. After that period, the symptom no longer occurs. Note that the symptom is platform-independent.
Workaround: To prevent the symptom from occurring, enter the no aaa accounting system guarantee-first command on the router before you reload the router. Doing so enables the tunnels to be terminated in the correct VPDN groups.
After the symptom has occurred, clear each of the affected tunnels by entering the clear vpdn tunnel id local-id command. Then, after the tunnels have been re-established, you should be able to terminate them in the correct VPDN groups.
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Symptoms: A PRE may crash.
Conditions: This symptom is observed rarely on a Cisco 10000 series that is configured for PPP and occurs when many serial links flap.
Workaround: There is no workaround.
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Symptoms: The number of SHDB handles for PPP, SIP, and a Cisco CallManager may increase considerably on the active RP. In this situation, when a switchover occurs, many interfaces may end up in the up/down state.
Conditions: This symptom is observed on a Cisco router that has dual RPs in a situation in which 1000 serial interfaces flap every 12 seconds for 10 hours.
Workaround: There is no workaround.
Resolved Caveats—Cisco IOS Release 12.2(31)SB2
All the caveats listed in this section are resolved in Cisco IOS Release 12.2(31)SB. This section describes only severity 1, severity 2, and select severity 3 caveats.
Note
Basic System Services
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Symptoms: A RADIUS progress code is incorrectly reported for a call that fails at IPCP. The progress code reports that the Link Control Protocol (LCP) is the open state.
Conditions: This symptom is observed on a Cisco platform that runs Cisco IOS Release 12.4(3a) and that is configured for AAA. The symptom is not release-specific.
Workaround: There is no workaround.
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Symptoms: A memory leak may occur on a router that is configured with 11,000 PPPoA and PPPoEoA sessions.
Conditions: This symptom is observed when AAA HA is used to synchronize the authorization data from the standby RP to the active RP and when a RADIUS server is used.
Workaround: Use local authentication. If this is not an option, there is no workaround.
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Symptoms: A RADIUS packet that is sent to a RADIUS server may contain a corrupted attribute.
Conditions: This symptom is observed on a Cisco router that is configured for AAA and that has the radius-server vsa send authentication command enabled.
Workaround: Disable the radius-server vsa send authentication command.
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Symptoms: Sessions are not properly synchronized from the active RP to the standby RP after an HA switchover has occurred.
Conditions: This symptom is observed on a Cisco router that has the no aaa new-model command enabled.
Workaround: Configure local authentication and enter the aaa new-model command. If this is not an option, there is no workaround.
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Symptoms: An "%AAA-3-ACCT_LOW_MEM_TRASH" error message is generated when a low-memory condition occurs. When this situation occurs, a memory leak may occur in AAA data.
Conditions: This symptom is observed when an interface flaps and causes a very large number of sessions to go down simultaneously, in turn generating a very large number of accounting stop records. In this situation, the I/O memory may be held for a long time when accounting records are send and when an AAA server is slow or unreachable.
Workaround: There is no workaround.
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Symptoms: A router that is configured for NetFlow v9 may reload unexpectedly because of a bus error.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2(25)S4 or Release 12.2(27)SBC1 when the configuration is modified while the router actively exports flows. The symptom may also occur in other releases.
Workaround: There is no workaround.
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Symptoms: A memory leak may occur in the RADIUS process on a router that is configured for dot1x authentication but that does not have the aaa authentication dot1x command enabled. The memory leak may consume all free memory.
Conditions: This symptom is observed when the router receives attribute 24 (state) or attribute 25 (class) from a RADIUS server.
Workaround: There is no workaround.
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Symptoms: The following error message and a traceback may be generated on a Cisco 7200 series:
%SYS-3-MGDTIMER: Uninitialized timer, set_exptime, timerConditions: This symptom is observed when you perform an OIR of a channelized port adapter, when you configure a channel group on channelized interfaces of a channelized port adapter, or when you enter the shutdown interface configuration command followed by the no shutdown interface configuration command on any interface.
Workaround: There is no workaround.
Further Problem Description: The symptom does not occur on a Cisco 7200 series that has an NPE-G2.
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Symptoms: An ISG crashes when a Change of Authorization (CoA) is issued upon account logon.
Conditions: This symptom is observed on a Cisco router that functions as an ISG while the password attribute is sent in the Account-Logon request.
Workaround: There is no workaround.
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Symptoms: When a PTA session is created with a traffic classifier (TC) service, the Parent-Session-ID attribute of the accounting packets of the TC service on the ISG does not match the Acct-Session-Id of the parent session after 16^2 (that is, 000000EE) Acct-Session-Ids have been used.
Conditions: This symptom is observed on a Cisco router that functions as an ISG and that is configured with QinQ subinterfaces over which PTA sessions are established.
Workaround: There is no workaround.
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Symptoms: The radius-server attribute 31 remote-id command does not function. The expected value of attribute 31 in a RADIUS Access-Request and Accounting-Request is only the value of the remote ID. However, attribute 31 may contain the host name, domain name, subinterface and description, in addition to the remote ID.
Conditions: This symptom is observed on a Cisco router that functions as a NAS and that has the radius-server attribute 31 remote-id command enabled.
Workaround: There is no workaround.
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Symptoms: Specifically-crafted CDP packets may cause a router to allocate and hold extra memory. Exploitation of this behavior by sending multiple specifically-crafted CDP packets may cause memory allocation problems on the router.
Conditions: This symptom is observed on a Cisco router when the header length of the CDP packet is shorter than the predefined header length (which is 4 bytes) and when the router runs a Cisco IOS software image that integrates the fix for CSCse85200.
A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCse85200. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Workaround: Disable CDP on interfaces where CDP is not required.
Further Problem Description: Because CDP is a Layer-2 protocol, the symptom can only be triggered by routers that reside on the same network segment.
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Symptoms: When AAA and High Availability (HA) are configured, "SHDB handles" are not properly released when the no aaa new-model command is enabled on the router. For each session (that is, each PPPoA or PPPoE session) that comes up, a new "SHDB handle" is allocated. However, when the session goes down, the "AAA HA code" fails to release the handle. This situation causes the router to use up all valid handle names, and, after that has occurred, to either generate tracebacks for each session that is created or to crash.
Conditions: This symptom is observed for each session that calls the "AAA HA code" to handle redundancy.
Workaround: Enable the aaa new-model command and configure local authentication. If this is not an option, there is no workaround.
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Symptoms: After a network event such as an HA switchover or an interface failure has occurred, information for all PPP sessions may be lost, causing the router to send RADIUS account-start messages for all PPP sessions and causing the RADIUS server to be severely stressed.
Conditions: This symptom is observed on a Cisco router that is configured for AAA.
Workaround: There is no workaround.
Further Problem Description: The fix for this caveat relieves the impact on the RADIUS server by enabling you to limit the maximum number of outstanding active RADIUS accounting request via the AAA accounting throttling command that is introduced below. This command is introduced not only for HA configurations but for general AAA operations.
radius-server throttle accounting requests
The requests argument limits the number of pending accounting start/stop requests that are sent by the router to the RADIUS server. For example, if the requests argument has a value of 25, the number of pending accounting start/stop requests (without a RADIUS acknowledgement) is at maximum 25. If a new accounting request must be processed and the router has already sent 25 requests, the router will attempt to send the new accounting request after a "timeout". The request will be delayed with the value in seconds that is entered in the timeout argument of the following command:
radius-server timeout timeout
The router does not discard these accounting request if they time-out. Only if the router has actually attempted to send the accounting request to the RADIUS server and has retransmitted it three times, the accounting request may be discarded. Note that the retransmit default is three but can be modified through the radius-server retry retries command.
If an accounting request is throttled, statistics are not impacted in any way. The statistics are updated only if an accounting request is sent to the RADIUS server, not when it is being throttled. You can check for the active accounting requests by entering the following command:
show aaa servers
Note that accounting has no impact on call setups. From the perspective of a client, it is a "send-and-forget" situation. The success or failure of accounting does not impact the actual session.
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Symptoms: When you perform an OIR of a POS port adapter, a TLB Exception error may occur and the router may reset.
Conditions: This symptom is observed on a Cisco router that has a POS port adapter with an interface that functions as an MPLS link in an AToM configuration when the POS interface has the mpls ip command enabled.
Workaround: First disable the mpls ip command on the POS interface, then remove the AToM (Xconnect) configuration from the interface, and then perform an OIR of the POS port adapter.
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Symptoms: The tacacs-server directed-request command appears in the running configuration when is should be disabled. When you disable the command by entering no tacacs-server directed-request and reload the router, the command appears to be enabled once more.
Conditions: This symptom is observed on a Cisco router that runs a Cisco IOS software image that integrates the fix for CSCsa45148, which disables the tacacs-server directed-request command by default.
A list of the affected releases can be found at http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsa45148. Cisco IOS software releases that are not listed in the "First Fixed-in Version" field at this location are not affected.
Temporary Workaround: Each time after you have reloaded the router, disable the command by entering no tacacs-server directed-request.
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Symptoms: A router may unexpectedly send an ARP request from all its active interfaces to the nexthop of the network of an SNMP server.
Conditions: This symptom is observed on a Cisco router that has the snmp-server host command enabled after any of the following actions occur:
–
–
–
Workaround: There is no workaround.
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Symptoms: The parent session Accounting STOP record is missing RADIUS attributes 42,43, 47 and 48.
Conditions: This symptom is observed on a Cisco router that is configured to terminate a PPP over Ethernet over L2TP session when you apply a service policy to the session. The symptom occurs only when the session is configured with at least one traffic classification with per-flow accounting.
When the PPP over Ethernet client is terminated, the RADIUS attributes 42, 43, 47 and 48 are missing from the parent session Accounting STOP record.
Workaround: There is no workaround.
EXEC and Configuration Parser
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Symptoms: The RP may crash with a watchdog timeout error for the IP input process.
Conditions: This symptom is observed on a Cisco router when you delete a subinterface that processes traffic.
Workaround: Shut down the subinterface before you delete the subinterface.
IBM Connectivity
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A vulnerability exists in the Data-link Switching (DLSw) feature in Cisco IOS where an invalid value in a DLSw message could result in a reload of the DLSw device. Successful exploitation of this vulnerability requires that an attacker be able to establish a DLSw connection to the device.
There are workarounds available for this vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070110-dlsw.shtml.
Interfaces and Bridging
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Symptoms: All packets are dropped from a 1-port OC-3/STM-1 POS port adapter (PA-POS-1OC3) or 2-port OC-3/STM-1 POS port adapter (PA-POS-2OC3) that is configured for CBWFQ.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G1. However, the symptom may be platform-independent.
Workaround: There is no workaround.
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Symptoms: A router may crash when one of its multipoint interface enters the up state.
Conditions: This symptom is observed on a Cisco 7200 series when the multipoint interfaces are configured for AAL5SNAP encapsulation via a virtual template and occurs only when the debug atm event command is enabled.
Workaround: There is no workaround.
IP Routing Protocols
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Symptoms: A router that is configured for PAT may generate the following error message and traceback while reporting slowness in the network:
%SYS-2-INTSCHED: `may_suspend' at level 3
-Process= "IP NAT Ager", ipl= 3, pid= 118
-Traceback= 80507F58 81310988 80CC14F8 80CD4F80 80CBAD30 80CBAD90 81321684 80CBB048 80504118 805085E0Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.3(4)T and that has a high number (more than 2500) of NAT entries. The symptom is not release-specific.
Workaround: There is no workaround.
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Symptoms: A CE router that has L2TP tunnels in an MPLS VPN environment with about 1000 VRFs may crash and generate the following error message:
Address Error (load or instruction fetch) exception, CPU signal 10, PC = 0x50766038Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.0(32)S and that functions as a CE router when BGP neighbors are unconfigured via the no neighbor ip-address command while the show ip bgp summary command is entered from the Aux console. The symptom is not release-specific and may also affect other releases.
Workaround: There is no workaround.
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Symptoms: A router that is configured for HA may crash shortly after a switchover has occurred. When this situation occurs, "%TCP-2-INVALIDTCB" error messages are generated.
Conditions: This symptom is observed on a Cisco router that has many interfaces (1600) that are connected to BGP neighbors when some peers are configured for NSR and others for NSF. The higher the number of interfaces on the router, the more likely it is that the symptom occurs.
Workaround: There is no workaround.
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Symptoms: A router that is configured for BGP and that has the ip policy-list command enabled may unexpectedly reload because of a bus error or SegV exception.
Conditions: This symptom is observed when BGP attempts to send an update with a "bad" attribute.
Workaround: There is no workaround.
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Symptoms: Prefixes that are tagged with Site of Origin (SoO) values may not be filtered at the border.
Conditions: This symptom is observed when SoO values are configured for a peer group. The peer group members may not correctly filter the prefixes that are based on the SoO value at the border.
Workaround: BGP supports Dynamic Update peer groups, which ensure that packing is as efficient as possible for all neighbors regardless of whether or not they are peer-group members.
Peer groups simplify configurations, but peer-templates provide a much more flexible solution to simplify the configuration than peer groups.
If the SoO configuration is applied directly to the neighbor or to a template, the symptom does not occur. Using templates to simplify the configuration is a better solution and Dynamic Update peer groups ensure efficiency.
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Symptoms: PPPoEoQinQ sessions fail to reconnect.
Conditions: This symptom is observed on a Cisco router that has 31,000 sessions when there is one session per subinterface. The symptom occurs when you shut down the main interface, bring it up again, and then attempt to reconnect the PPPoEoQinQ sessions.
Workaround: There is no workaround.
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Symptoms: The BGP table version remains stuck at 1, and the router may crash.
Conditions: This symptom is observed when you enter the clear bgp ipv4 uni * command for IPv4 or the clear bgp ipv6 uni * command for IPv6. The symptom may also occur when you enter the clear bgp nsap uni * command for a network service access point (NSAP) address family.
Workaround: Enter the clear ip bgp * command to clear the sessions, purge the BGP table, and prevent the router from crashing.
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Symptoms: A router may hang when you send a VRF ping to an outside NAT address of a directly-connected router.
Conditions: This symptom is observed on a Cisco router that is configured for VRF NAT.
Workaround: There is no workaround.
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Symptoms: A label mismatch may occur between the CEF table and the BGP table, and a new label may not be installed into the CEF table.
Conditions: This symptom is observed after a BGP flap has occurred on a Cisco router that is configured or MPLS VPN but that does not function in an inter-autonomous system and that does not have multiple VRFs.
Workaround: There is no workaround. After the symptom has occurred, enter the clear ip route command for the affected VRF.
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Symptoms: A router that is configured for NAT Overload may crash while performing dynamic translation from many ports to one port.
Conditions: This symptom is observed after more than 5000 translations have been performed.
Workaround: There is no workaround.
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Symptoms: After you have removed a loopback interface from the configuration on the primary RP while the same loopback interface is required as part of another configuration, for example, as an update source for a BGP neighbor, the standby RP does not reload successfully when you reset it.
Conditions: This symptom is observed on a Cisco router and occurs only in an HA environment.
Workaround: Remove all configurations that reference the loopback interface before you remove the loopback interface.
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Symptoms: When an RP switchover occurs or when a standby RP resets, the standby RP may enter a loop in which it reboots continuously because of a BEM error.
Conditions: This symptom is observed on a Cisco router that has the router rip and address-family ipv4 commands enabled but that does not have a network command as part of the address-family configuration.
Workaround: Disable the router rip command.
Miscellaneous
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Devices running Cisco IOS versions 12.0S, 12.2, 12.3 or 12.4 and configured for Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs) or VPN Routing and Forwarding Lite (VRF Lite) and using Border Gateway Protocol (BGP) between Customer Edge (CE) and Provider Edge (PE) devices may permit information to propagate between VPNs.
Workarounds are available to help mitigate this vulnerability.
This issue is triggered by a logic error when processing extended communities on the PE device.
This issue cannot be deterministically exploited by an attacker.
Cisco has released free software updates that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are available.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20080924-vpn.shtml.
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Symptoms: When the ifStackStatus object of an inverse multiplexing over ATM (IMA) interface is polled with an "snmpwalk," an endless loop may occur.
Conditions: This symptom is observed on a Cisco router that is configured with an 8-port ATM Inverse MUX E1 or T1 port adapter (PA-A3-8E1IMA or PA-A3-8T1IMA).
Workaround: There is no workaround.
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Symptoms: CPUHOG tracebacks may be generated when you bring up 30,000 PPPoE sessions and then remove an input policy map from a virtual template on a broadband PTA.
Conditions: This symptom is observed on a Cisco router that functions as a broadband PTA and that is configured with 31,500 ATM subinterfaces, an input policy map, an output policy map with an CBWFQ policy, and 128,000 queues.
Workaround: There is no workaround.
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Symptoms: A router crashes when the encapsulation is changed from AAL5SNAP to AAL0.
Conditions: This symptom is observed when the encapsulation is changed on a private virtual circuit (PVC).
Workaround: Do not configure AAL0.
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Symptoms: As a user of a router, you cannot authenticate or authorize via a TACACS+ server. A TCP SYN that is sent from the router to port 49 of the TACACS+ server carries an incorrect source IP address. Instead of the address that is specified in the ip tacacs source-interface subinterface-name command, the router uses the default address for login authentication and exec authorization. The nondefault source interface is correctly used for command authorization.
Conditions: This symptom is observed on a Cisco router that is configured to use a nondefault source interface to connect to a TACACS+ server when there is at least one authentication or authorization method list configured to use one more TACACS+ servers and when the following command sequence is enabled:
aaa new-model
tacacs-server host host-ip-address
tacacs-server key key
ip tacacs source-interface subinterface-name
Workaround: Remove the ip tacacs source-interface subinterface-name command.
Further Problem Description: Protocols other than TACACS+ that use TCP and that are implemented via the sockets library may also use an incorrect source address when they are configured to use a nondefault source interface or address. This situation may cause problems, depending on the configuration of the router, the routing tables, and the configuration of the outside client or server with which the other protocol communicates. In Cisco IOS software images, most services that use TCP, including BGP, are not implemented via sockets but, instead, use a proprietary interface for the TCP protocol, and are not affected.
Some older versions of TACACS+ do not use sockets. In a Cisco IOS software image with such an older TACACS+ version, TACACS+ is not affected but other services may still be affected.
Workaround for protocols other than TACACS+: Remove the configuration that specifies a source interface or source address from the router.
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Symptoms: When a CEF initialization failure occurs, an ATM PVC that is configured for OAM may not pass traffic even though the PVC link status is up:
Router#show ip interface brief | include ATM
ATM3/0/0 unassigned YES manual up up
ATM3/0/0.100 unassigned YES unset up up
ATM3/0/0.300 10.1.1.1 YES manual up up
ATM3/0/0.999 unassigned YES unset up up
Router#show cef interface brief | include ATM
ATM3/0/0 unassigned up dCEF
ATM3/0/0.100 unassigned down dCEF
ATM3/0/0.300 10.1.1.1 down dCEF
ATM3/0/0.999 unassigned down dCEF
Router#show ip cef | include 10.1.1.
10.1.1.0/30 attached ATM3/0/0.300When CEF fails to initialize the ATM PVC, atm3/0/0.300, no /32 receive entries are created. Traffic that is destined for the IP address of the subinterface is dropped.
Conditions: This symptom is observed on a Cisco router and occurs only when PAM is configured on the PVC.
Workaround: To prevent the symptom from occurring, do not configure OAM on the PVC. When the symptom has occurred, enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the affected ATM subinterface. After the workaround has been applied, the output of the show ip cef command shows the following:
Router#show ip cef | include 10.1.1.
10.1.1.0/30 attached ATM3/0/0.300
10.1.1.0/32 receive
10.1.1.1/32 receive
10.1.1.3/32 receive•
Symptoms: After an SSO switchover has occurred, the following error message may be generated:
LSD-4-LABEL_RESOURCE: label range 16-524287 exhaustedConditions: This symptom is observed on a Cisco router that functions in an MPLS configuration under a heavy traffic load that causes bulk synchronization to take a relatively long time. The symptom occurs when there is label allocation between the "bulk-sync-done" state and the "Standby Hot" state.
Workaround: There is no workaround.
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Symptoms: Unicast Reverse Path Forwarding (uRPF) does not function for a PPP subscriber when the ip portbundle command is enabled on the interface that carries the subscriber session. The following example shows a configuration in which the symptom occurs:
interface Serial3/0
ip vrf forwarding vrf1
ip address x.x.x.x y.y.y.y
ip verify unicast source reachable-via rx <***** uRPF enabled
encapsulation ppp
service-policy type control ipsub-authIn the above-mentioned example, if the ip portbundle command is enabled in the "ipsub-auth" policy map, the source address of the interface that carries the subscriber traffic is changed to one of the IP addresses of the ISG, and the reverse-path check causes the traffic to be dropped.
Conditions: This symptom is observed on a Cisco router that functions as an ISG.
Workaround: Disable the uRPF.
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Symptoms: After a service policy is removed from the virtual template, the same policy is not automatically removed from the virtual-access interface.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB or Release 12.2(27)SBC.
Workaround: Clear the virtual-access interface.
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Symptoms: A router may crash when you disassociate a VRF from an MPLS interface.
Conditions: This symptom is observed on a Cisco router that is configured for L2TP when you enter the no ip vrf forwarding vrf-name command.
Workaround: There is no workaround.
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Symptoms: The standby PRE-2 crashes because of a debug exception, and the standby PRE-2 console shows the following error messages and traceback before the crash occurs:
%SYS-2-ASSERTION_FAILED: Assertion failed: "(*parents_ptr)->coll_magic == COLL_MAGIC_VAL"
-Process= "Deferred Adj Background", ipl= 0, pid= 167
-Traceback= 6050CA04 604AA1B4 60362364 60362510 603630A4 6035B67C 60360598 60FFAB30 60FF54A0 60FF5578
%Software-forced reloadConditions: This symptom is observed on a Cisco 10000 series after an ATM line card is reset.
Workaround: There is no workaround.
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Symptoms: The standby PRE reloads unexpectedly.
Conditions: This symptom is observed on a Cisco 10000 series when either of the following events occur:
–
–
Workaround: There is no workaround.
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Symptoms: During an HA configuration synchronization a router may generate the following error message:
%UTIL-3-TREE: Data structure error--attempt to reference an uninitialized wavl treeConditions: This symptom is observed rarely on a Cisco router when auto-discovery packets are received by the router during the initialization phase after an HA switchover has occurred or after the router has reloaded for the first time.
Workaround: There is no workaround.
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Symptoms: The queueing hierarchy is not removed when it should be removed, even though the output of the show policy-map interface command indicates that the queueing hierarchy is removed.
Conditions: This symptom is observed when you detach a service policy that has queueing features in the policy map.
Workaround: There is no workaround.
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Symptoms: A PTA router may crash when you download a configuration with a class map, policy map, and PVC range to a point-to-point interface.
Conditions: This symptom is observed on a Cisco 10000 series that functions as a PTA router.
Workaround: There is no workaround.
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Symptoms: An RP may hang when PPPoX sessions are brought up.
Conditions: This symptom is observed after an HA switchovers has occurred.
Workaround: There is no workaround.
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Symptoms: A router crashes when you modify a police in the parent policy map.
Conditions: This symptom is observed on a Cisco 10000 series when you first remove a class with a police that is configured under a parent policy map and then re-apply the same class or any other class with a police to the parent policy map.
Workaround: Remove the parent policy map, reconfigure the parent policy map, and the re-attach the parent policy map.
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Symptoms: The standby RP may generate "%SYS-2-MALLOCFAIL: Memory allocation" failures and may or may not reset repeatedly.
Conditions: These symptoms are typically observed in highly scaled configurations that consist, for example, of many BGP peers or PPPOA sessions. The symptoms occur during the SSO configuration-synchronization phase and bulk-synchronization phase when the standby RP comes online, during the configuration of the router, after a switchover, or when peer interfaces and/or routing neighbors flap. The symptom is more likely to occur on an RP that does not contain so much physical I/O memory and/or operates at a relatively slow CPU speed.
Workaround: Scale down the configuration, or reduce the number of BGP peers or PPPOA sessions. If the peer neighbors or interfaces flap, determine the root cause, and correct the flapping problem.
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Symptoms: A policer configuration may not be removable from a policy map.
Conditions: This symptom is observed on a Cisco 10000 series when policy-map classes have a priority level configured.
Possible Workaround: Remove the policy map, reconfigure the policy map, and then re-attach the policy map.
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Symptoms: ISSU negotiation or a bulk synchronization fails, causing the standby RP to reload.
Conditions: This symptom is observed on a Cisco router that is configured for HA when the ISSU client or DHCP client is not present on the peer.
Workaround: There is no workaround.
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Symptoms: There is no interception when a time-based ACL rule is inactive.
Conditions: This symptom is observed on a Cisco 10000 series that has the Lawful Intercept feature enabled.
Workaround: There is no workaround.
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Symptoms: A router may crash when QoS policy changes occur for a large number of VCs.
Conditions: This symptom is observed on a Cisco router when the QoS changes are made via an automated script.
Workaround: Modify the VCs manually, one by one.
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Symptoms: A Cisco 10000 series crashes when a scaled MFR configuration is loaded.
Conditions: This symptom is observed when you load the scaled MFR configuration by using TFTP via the copy tftp running-config command.
Workaround: There is no workaround.
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Symptoms: A router may crash when you first enter the ip portbundle command for PPPoE sessions in a port-bundle host key (PBHK) configuration and when you then change an ACL.
Conditions: This symptom is observed on a Cisco 10000 series that functions as an ISG and that has a configuration such as the following:
ip portbundle
length 3
match access-list 103
source Loopback2Workaround: There is no workaround.
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Symptoms: A Cisco router that functions as an Intelligent Service Gateway (ISG) may reload while sessions are being cleared.
Conditions: This symptom is observed only when the port-bundle host key (PBHK) feature is configured for the sessions.
Workaround: Do not configure the PBHK feature for the sessions.
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Symptoms: A Cisco 7200 series may crash when you configure an IPv6 address on an interface.
Conditions: This symptom is observed on a Cisco 7200 series that has the Lawful Intercept feature enabled.
Workaround: There is no workaround.
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Symptoms: Attachment circuit (AC) and AToM clients show up as compatible while they have no peer on the other side.
Conditions: This symptom is observed on a Cisco router that is configured for In-Service Software Upgrade (ISSU) when you downgrade from Cisco IOS Release 12.2(31)SB to Cisco IOS Release 12.2(28)SB or one of it's rebuilds.
Workaround: There is no workaround.
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Symptoms: A router may reload after receiving a malformed UDP packet on port 67.
Conditions: This symptom is observed on a Cisco router that functions as an DHCP server.
Workaround: There is no workaround.
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Symptoms: When you convert a non-queueing policy map to a queueing policy map and attach it to interfaces that do not support queuing, the QoS policy is removed from the interfaces and existing sessions.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: Convert the non-queueing policy map to a queueing policy map before you apply it to interfaces or bring up sessions.
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Symptoms: E1 interfaces may go down when a line card is reset or removed even when the line card has APS enabled and an APS cutover is triggered. The interfaces do come back up within a few seconds.
Conditions: This symptom is observed on a Cisco 10000 series that has a pair of 4-port channelized OC-3 line cards that are configured for SR-APS. The line cards are configured with E1 interfaces under either SONET or SDH.
Workaround: Enter the force command in APS group configuration mode on both the router on which the line card is reset or removed and on the router at the far end to ensure that the line card that is reset or removed does not receive or transmit the active traffic.
Note that the chances of the symptom occurring may be reduced when the line card that is reset or removed is not the active line card.
Further Problem Description: This symptom occurs only when a line card is reset or removed, not when an APS switchover is triggered by a fiber cable that is removed.
The symptom occurs because of a change in the E1 clock source that may occur when the line card is reset or removed and that causes alarms to be received. The symptom is more likely to occur when the line card has a large configuration and when the E1 interfaces are set to "clock source line."
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Symptoms: When you upgrade the Cisco IOS software image from Cisco IOS Release 12.2(28)SB3 to Cisco IOS Release 12.2(31)SB by entering the issu loadversion command, the standby RP remains in the RPR mode, preventing the upgrade from proceeding.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: When you reload a Cisco 10000 series that has dual PREs, the standby PRE may crash during the boot process and may or may not generate a traceback.
Conditions: This symptom is observed on a Cisco 10000 series that has a large configuration when the standby PRE and primary PRE are out of synchronization while you enter the reload command.
Workaround: There is no workaround.
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Symptoms: A Cisco 7304 series NPE-G100 may hang.
Conditions: This symptom is observed when a cache exception occurs, which is a very rare event.
Workaround: There is no workaround.
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Symptoms: When an IP session that was initiated by DHCP goes down, the session cannot be reconnected until the lease expires for the client.
Conditions: This symptom is observed on a Cisco Intelligent Service Gateway (ISG) when an idle-timeout occurs, when the ISG reloads, or when a client logs off without releasing the IP address.
Workaround: Manually clear the DHCP binding or just wait until the lease expires.
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Symptoms: The Hierarchal Queuing Framework (HQF) is not removed after you have removed a service policy.
Conditions: This symptom is observed on a Cisco 7200 series that has an NPE-G1 and that runs Cisco IOS Release 12.2SB.
Workaround: There is no workaround.
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Symptoms: A Cisco 7200 series may send a corrupted packet via a 2-port T3 serial, enhanced port adapter (PA-2T3+). The rate of corrupted packets is very low.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2SB, Release 12.4T, or Release 12.4(4)XD3 and occurs when the router functions under high stress conditions such as a high CPU load and an oversubscribed interface of the PA-2T3+.
Workaround: Avoid a high CPU load and oversubscription of the interface of the PA-2T3+.
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Symptoms: On a Cisco 10000 series, tracebacks and an error message that is related to the link index may be generated, and MLPoATM links continue to flap. The error message is similar to the following:
%GENERAL-3-EREVENT: ttcm_add_mlp_member: 1926 No free link index available in Virtual-Access15Conditions: This symptom is observed when a member link of an MLPoATM bundle is modified.
Workaround: There is no workaround.
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Symptoms: The circuit ID and remote ID of option 82 in a DHCP relay reply message may be empty and may cause a DHCP relay reply validation error, resulting in a DHCP lease renewal failure.
Conditions: This symptom is observed on a Cisco router that functions as an ISG when an IP session that is initiated by DHCP involves a VRF transfer.
Workaround: There is no workaround.
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Symptoms: When you reload a Cisco 10000 series, tracebacks are generated when the router comes back up.
Conditions: This symptom is observed when the router has dual PREs that function in SSO mode and a 4-port channelized STM-1/OC-3 line card that is configured for Multi-Router APS (MR-APS).
Workaround: There is no workaround.
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Symptoms: A traceback may be generated during the "fetch_interface_drop_stats_clrable" process on a Cisco 10000 series.
Conditions: This symptom is observed when you enter the clear pxf interface command for an inactive multilink interface.
Workaround: Enter the clear pxf interface command only when the multilink interface is active.
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Symptoms: A Cisco 10000 series may crash because of an address error (that is, a load or instruction fetch exception) when multiple combined command-line interface (CLI) changes are made.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for RPR+ when you attempt to make multiple policy map changes on a PVC that has a small number of active sessions with a moderate amount of downstream traffic.
Workaround: There is no workaround.
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Symptoms: The output of the show ip subscriber command does not show the sessions.
Conditions: This symptom is observed on a Cisco router that functions as an Intelligent Service Gateway (ISG) and occurs for IP session with a static IP address that are connected via Layer 2.
Workaround: Do not enter the show ip subscriber command. Rather, enter the show ip subscriber mac command.
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Symptoms: When the debug ip subscriber event or debug ip subscriber all command is enabled and when a client attempts to establish an IP session, the Cisco Intelligent Service Gateway (ISG) may crash.
Conditions: This symptom is observed on a Cisco router that functions as an ISG under the following conditions:
–
–
–
Workaround: Disable the debug ip subscriber event or debug ip subscriber all command.
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Symptoms: An RP may crash when PPP sessions with service policies are removed. If the router is configured with a standby RP, a switchover may occur. Then, if more PPP sessions are removed, the newly active RP may crash. These symptoms may also occur when you enter the no policy-map command for a policy map that is attached as a service policy to many PPP sessions.
Conditions: These symptoms are more likely to occur with a large number of sessions (tens of thousands or more) and when the session are removed at a high rate (hundreds per second).
Workaround: There is no workaround.
Further Problem Description: The symptoms are caused by a race condition when internal processes, such as statistics updates, may attempt to modify data that are related to service policies that are being removed.
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Symptoms: VCs may enter an inactive state, preventing sessions from coming up over the VCs.
Conditions: This symptom is observed on a Cisco 10000 series when you perform an OIR of the line card on which the VC are configured after at least one HA switchover has occurred.
Workaround: Reload the router.
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Symptoms: An ATM line card may reset after when an SSO switchover occurs.
Conditions: This symptom is observed on a Cisco 10000 series when an SSO switchover occurs while there are 32,000 active PPP over ATM (PPPoA) sessions.
Workaround: There is no workaround.
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Symptoms: A Network Processing Engine G1 (NPE-G1) may restart unexpectedly and report the following message:
Last reset from watchdog resetConditions: This symptom is observed only on Cisco 7200 and Cisco 7301 series routers that are configured with an NPE-G1 Network Processing Engine.
Workaround: There is no workaround.
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Symptoms: Incorrect police percent conversions occur in the second and third level of a policy.
Conditions: This symptom is observed on a Cisco 7200 series that runs Cisco IOS Release 12.2SB but may also occur on other platforms and in other releases.
Workaround: There is no workaround.
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Cisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml.
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.
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Cisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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–
–
Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml.
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.
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Symptoms: When a VC that is configured under a VP goes down, PPPoE sessions can still be established over the VC.
Conditions: This symptom is observed on a Cisco 10000 series after you have entered the shutdown interface configuration command followed by the no shutdown interface configuration command on the main interface or after you have reloaded the router.
Workaround: There is no workaround.
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Symptoms: A Cisco 10000 series may crash and generate one of the following error messages:
PXF DMA Error - Command Packet Handle Out of Rangeor:
PXF DMA - Small Free Packet Handle Access Out of RangeConditions: This symptom is observed on a Cisco 10000 series that processes L2TP traffic and that has a heavy CPU load.
Workaround: There is no workaround.
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Symptoms: When a Cisco 7304 has a configuration with more than 65,536 ACEs, some of the counters do not increment correctly.
Conditions: This symptom is observed when the entire ACE configuration is greater than 65,336 ACEs.
Workaround: There is no workaround. Do not configure more than 65,536 ACEs.
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Symptoms: Alignment errors may occur when you detach a shaping service policy from a QinQ subinterface.
Conditions: This symptom is observed on a Cisco 10000 series.
Workaround: There is no workaround.
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Symptoms: When a two-level hierarchical policy map in which the parent level has only a class default is already attached to an interface and when you configure a policer for both the parent and child levels, either of the following symptoms may occur:
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Conditions: This symptom is observed on a Cisco 10000 series that runs Cisco IOS Release 12.2SB.
Workaround: After the child policy is removed from or attached to the parent policy map, detach the policy map from the interface and re-attach it to the interface.
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Symptoms: When you enter the issu loadversion active-slot active-image standby-slot standby-image command, the active RP may crash.
Conditions: This symptom is observed rarely on a Cisco 10000 series that functions in SSO mode. The symptom may be platform-independent.
Workaround: There is no workaround.
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Symptoms: When an RPR switchover occurs, a router may generate CPUGHOG messages or may crash because of a watchdog timeout.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS Release 12.2SB or Release 12.2SR.
Workaround: There is no workaround.
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Symptoms: A router may crash when you enter the connect command.
Conditions: This symptom is observed when one of the VCs that is being configured in the connect command is down.
Workaround: Ensure that both VCs are up when you enter the connect command.
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Symptoms: When a GRE IP tunnel is configured between a CE router and a PE router and is added to the VRF table, the IP address of the tunnel on the PE router is not reachable from the CE router although the IP address of the tunnel on the CE router is reachable from the PE router.
Conditions: This symptom is observed on a Cisco 7304 that has an NSE-100 and that functions as a PE router.
Workaround: There is no workaround.
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Symptoms: A router crashes when you enter the ip rtp header compression command on a serial interface that has a service policy attached.
Conditions: This symptom is observed on a Cisco router and occurs only when a routing protocol, such as EIGRP, has been configured.
Workaround: There is no workaround.
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Symptoms: When a PVC is shut down on the remote side, the PVC subinterface on a router transitions from the down state to the up state within one second, but then remains in the down state after the down retry timers expire.
Conditions: This symptom is observed on a Cisco router that is configured for Operation, Administration, and Maintenance (OAM) and Dynamic Bandwidth Selection (DBS).
Workaround: There is no workaround.
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Symptoms: Multilink class 0 is used for all outgoing packets, regardless of which encapsulation sequence is configured for a queue.
Conditions: This symptom is observed on a Cisco 10000 series that is configured for Multiclass MLP (MC-MLP) with one member link and occurs after the PXF engine is reloaded.
Workaround: There is no workaround.
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Cisco IOS device may crash while processing malformed Secure Sockets Layer (SSL) packets. In order to trigger these vulnerabilities, a malicious client must send malformed packets during the SSL protocol exchange with the vulnerable device.
Successful repeated exploitation of any of these vulnerabilities may lead to a sustained Denial-of-Service (DoS); however, vulnerabilities are not known to compromise either the confidentiality or integrity of the data or the device. These vulnerabilities are not believed to allow an attacker will not be able to decrypt any previously encrypted information.
Cisco IOS is affected by the following vulnerabilities:
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–
–
Cisco has made free software available to address these vulnerabilities for affected customers. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070522-SSL.shtml.
Note
A combined software table for Cisco IOS is available to aid customers in choosing a software releases that fixes all security vulnerabilities published as of May 22, 2007. This software table is available at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20070522-cry-bundle.shtml.
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Symptoms: When you enter the show atm vp command for ATM VPs, a negative number of data VCs is displayed, which does not represent the actual number of VCs per VP.
Conditions: This symptom is observed on a Cisco 10008 that runs Cisco IOS Release 12.3(7)XI. However, the symptom is not platform-specific, nor release-specific.
Workaround: There is no workaround.
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Symptoms: The following error message and traceback may be displayed:
%XDR-6-CLIENTISSUBADTXTFM: Failed to xmit_transform message - to slot 6, client CEF push, context 0
-Traceback= 41437E50 4141D584 41432B64 4141D674 41421558 414219DC 41416388 413F4738 413F4EA0 403E11D0 402652A8 40402AD0 404F23F8 404F23E4Conditions: This symptom is observed on a Cisco router that is configured for SSO and that has dCEF enabled by default. The symptom occurs when you disable dCEF and then re-enable it, for example by entering the no ip cef command followed by the ip cef distributed command or the no ip routing command followed by the ip routing command.
Workaround: There is no workaround.
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Symptoms: When you apply a channel group to a Gigabit Ethernet interface that has the negotiation auto command enabled, the negotiation auto command is unexpectedly enabled on the port-channel interface. This situation causes a synchronization failure on the standby RP, in turn, causing the standby RP to reset.
Conditions: This symptom is observed on a Cisco router that has redundant RPs in an HA configuration.
Workaround: Manually remove the auto-negotiation configuration from the port-channel interface by entering the no negotiation auto command.
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Symptoms: When you configure MVPN over an MLPoATM interface, multiple PXF crashes may occur.
Conditions: This symptom is observed on a Cisco 10000 series when you first enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the MLPoATM interface and then enter the show pxf cpu queue