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Release Notes for Cisco IOS Release 15.2(1)GC2

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Release Notes for Cisco IOS Release 15.2(1)GC2

Table Of Contents

Release Notes for Cisco IOS Release 15.2(1)GC2

Contents

Image Information and Supported Platforms

Related Documentation

New and Changed Information

New Hardware Features

New Software Features

Limitations

Troubleshooting

Recommended Configuration Settings

Caveats

Cisco IOS Release 15.2(1)GC2

Open Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5915 and 5940 ESR

Cisco IOS Release 15.2(1)GC1

Open Caveats for the Cisco 5915 and 5940 ESR

Open Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5940 ESR

Cisco IOS Release 15.2(1)GC

Open Caveats for the Cisco 5915 and 5940 ESR

Open Caveats for the Cisco 5915 ESR

Open Caveats for the Cisco 5940 ESR

Obtaining Documentation, Support, and Security Guidelines


Release Notes for Cisco IOS Release 15.2(1)GC2


Current Release:
15.2(1)GC2 — May 9, 2012

Previous Releases:
15.2(1)GC1
15.2(1)GC

The following release notes support Cisco IOS Release 15.2(1)GC2. They are updated to describe new features, limitations, troubleshooting, recommended configurations, caveats, and how to obtain support and documentation.

Contents

This publication consists of the following sections:

Image Information and Supported Platforms

Related Documentation

New and Changed Information

Limitations

Troubleshooting

Recommended Configuration Settings

Caveats

Obtaining Documentation, Support, and Security Guidelines

Image Information and Supported Platforms

These images are bug compatible with Cisco IOS release 15.2(1)T1.

Cisco IOS Release 15.2(1)GC2 includes the following Cisco IOS images:

c2900-universalk9-mz.SPA

c2951-universalk9-mz.SPA

c3900-universalk9-mz.SPA

c3900e-universalk9-mz.SPA

c5915-adventerprisek9-mz.SPA

c5915-entbase-mz.SPA

c5940-adventerprisek9-mz.SPA

c5940-entbase-mz.SPA


Note You must have a Cisco.com account to download the software.


Cisco IOS Release 15.2(1)GC2 is supported on the following platforms:

Cisco 2901 Integrated Services Router

Cisco 2911 Integrated Services Router

Cisco 2921 Integrated Services Router

Cisco 2951 Integrated Services Router

Cisco 3925 Integrated Services Router

Cisco 3945 Integrated Services Router

Cisco 3945e Integrated Services Router

Cisco 5915 Embedded Services Router

Cisco 5940 Embedded Services Router

Related Documentation

The following documentation is available:

Software Configuration Guide, Cisco IOS Release 15.2(1)GC (OL-24065-01)

Mobile Ad Hoc Networks for Router-to-Radio Communications (OL-19437-02)

Software documentation for Cisco IOS Release 15.2(1)T

New and Changed Information

This section contains the following information:

New Hardware Features

New Software Features

New Hardware Features

No new hardware features are supported in 15.2(1)GC2.

The Cisco 5915 ESR was initially supported with 15.2(1)GC.

New Software Features

Cisco IOS Release 15.2(1)GC2 is based on Cisco IOS Release 15.2(1)T. Refer to the following URL for information on the new software features added to Release 15.2T: http://www.cisco.com/en/US/docs/ios/15_2m_and_t/release/notes/15_2m_and_t.html

Limitations

This release has the following limitations:

The Quality of Service (QoS) policy can only be applied to one outgoing interface the Point-to-Point Protocol over Ethernet (PPPoE) session is traversing.

A QoS output policy can be applied to the Virtual Template or the Virtual Multipoint Interface (VMI), but not at the same time. If a policy is attached, the outgoing physical interfaces (i.e., physical-interface FastEthernet0/0) should not have output policy applied. It is recommended that the policy be attached to the Virtual Template. The other option is to apply the policy to the VMI, but not to the Virtual Template or Ethernet interface.

When a service policy is applied to the VMI and packets are dropped on the VA due to credit starvation, the show policy-map int VMI command will not show these dropped packets. There is no back pressure between the interfaces in this configuration. The VMI does not know that packets were dropped by the Virtual Access (VA) or the Ethernet physical interfaces.

RFC 5578 credits do not tie into QoS formulas. Credits only indicate to QoS the ability to transmit a packet or not. If there are enough credits a packet will be transmitted from the highest priority queue. When there are not enough credits, packets will be queued.

QoS policy may drop on an interface when the interface receives an invalid CDR value.

To prevent dropping QoS policy, the current data rate (CDR) is range checked to a floor value of 10kbps and a ceiling value of the physical interface speed. If CDR is below the floor value, the QoS rate shaping is set to the floor value. If CDR is above the ceiling value, the QoS rate shaping is set to the ceiling value. The floor value is 10kbps. The ceiling value is limited to the physical interface speed.

In addition to defining floor and ceiling bandwidth values, the class bandwidth percentage must also be 10% or greater. If the class bandwidth is configured to a value less than 10% and the CDR value is less than 10kbps, the QoS policy will be removed (CSCth43582).

Software Release 15.2(1)GC may have OSPFv3 incompatibility issues while in Mobile Ad Hoc Networks (MANET) mode with software versions 12.4(24)GC or previous versions. To avoid any issues, ensure that all routers run the same version of Cisco IOS.

Cisco 5915 ESR has the following limitations:

The Virtual Local Area Network (VLAN) database is maintained in the flash as a file (vlan.dat). This file is created or updated only while adding, deleting, or modifying a VLAN to a switchport. Do not delete the vlan.dat file.

Copying a configuration, with switch ports configured with VLANs, through Trivial File Transfer Protocol (TFTP) to the Cisco 5915 ESR running configuration, the vlan.dat file may not be created automatically in flash. As a result, the VLANs configured in the switch ports do not exist, even though the running config shows the switch ports configured with VLANs. If a VLAN appears as 'Line protocol down' the VLAN association needs to be updated by configuring the VLAN database explicitly by entering the vlan vlan_number command.

When you copy any configuration file with VLAN configurations to TFTP server, back up the corresponding vlan.dat file to TFTP. And when you copy a configuration file from a TFTP server to the Cisco 5915 ESR, copy the corresponding vlan.dat file to C5915 router flash (CSCtq04969).

When you copy files to the flash, the copy process may become very slow when flash has limited free space. Delete unused files to free up space. If the issue persists, enter the format flash command to reclaim space from the deleted files (CSCtl42754).

The Output drops counter may not be accurate under stress. You can verify the number of output drops in output for the show controller command (CSCtl70552).

If a Cisco 5915 ESR router port is connected by a straight-through cable to another Cisco 5915 router port, the link does not come up when both the port speed and duplexing is forced on both ends. Use a cross-over cable or enable auto-negotiation on at least one of the connected router ports (CSCts12173).

Troubleshooting

Use the following command to collect data when reporting router issues:

show tech

Use the following command to collect data to confirm neighbor establishment:

show vmi neighbor

Use the following command to display active PPPoE sessions:

show pppoe session

Use the following command to examine QoS issues:

show policy-map interface virtual-access interface-number

Use the following commands to debug VMI issues:

debug vmi error

debug vmi pppoe

Use the following commands to verify PPPoE and VMI interface operation related to credit information:

show vmi neighbor detail

show pppoe session all

Use the following command to debug PPPoE issues:

debug pppoe error

Use the following command to display OSPFv3 traffic data including Link-State Advertisements (LSA) counts:

show ospfv3 traffic

Use the following command to display Enhanced Interior Gateway Routing Protocol (EIGRP) traffic data:

show ip eigrp traffic [as-number]

The following command is not supported, but may be useful in debugging EIGRP MANET metric issues:

debug eigrp neighbor

Use the following command to collect data when reporting ROMmon issues:

showmon

Complete the following procedure to collect data if a router reboot to ROMmon occurs:

1. dir flash: Use to locate the Route Processor (crashinfo*) or Network Processor (pxf_crashinfo*) exception file.

2. Email the exception file with a write up to the Cisco Beta support email address.

Recommended Configuration Settings

Use the following configuration guidelines when enabling class-based weighted fair-queuing:

Enter the following command to turn off creation of virtual-template subinterfaces:

no virtual-template subinterface
 
   

Enter the following commands to create a policy map with class-based weighted fair-queuing and apply the newly created policy-map to the virtual template:

class-map match-any chat
 match  dscp af11
class-map match-any voice
 match  dscp ef 
 
   
policy-map mypolicy
 class chat
  bandwidth percent 40
 class voice
  bandwidth percent 40
 
   
interface virtual-template number
service-policy output mypolicy
 
   

No additional configuration is supported on the policy-map.

Use the following configuration guidelines when disabling Point to Point Protocol (PPP) keepalives:

You can turn off the PPP keepalive messages to decrease overhead when the radio alerts the router with a PPPoE Active Discovery Terminate (PADT) message that the layer-2 RF connection is no longer available. Turning off the PPP keepalive messages may also avoid the potential for the router to terminate the connection based on missed PPP keepalives over a poor radio frequency (RF) link.

To turn off the PPP keepalive messages, enter the following command for the virtual-template:

interface virtual-template number
no keepalive 

Use the following configuration guidelines for setting the recommended Open Shortest Path First (OSPF) values of radio link metrics:

You may have to dampen the amount of changes in order to reduce network-wide churn because cost components may change rapidly.

The following recommended values are intended as a starting point for optimizing an OSPFv3 network and are based on network simulations that may reduce the rate of network changes. Each network may have unique characteristics that require different settings to optimize actual network performance.

You must configure these values for both OSPFv3 IPv4 and IPv6:

S1 = ipv6 ospf dynamic weight throughout
     Recommended value = 0
     Default=100
S2 = ipv6 ospf dynamic weight resources
     Recommended value = 29
     Default = 100
S3 = ipv6 ospf dynamic weight latency
     Recommended value = 29
     Default = 100
S4 = ipv6 ospf dynamic weight L2 factor
     Recommended value = 29
     Default = 100

The following is an example configuration for a VMI interface on the virtual template when running bypass mode:

interface vmi1
...
ipv6 ospf cost dynamic weight throughput 0
ipv6 ospf cost dynamic weight resources 29
ipv6 ospf cost dynamic weight latency 29
ipv6 ospf cost dynamic weight L2-factor 29
...
ospfv3 cost dynamic weight throughput 0
ospfv3 cost dynamic weight resources 29
ospfv3 cost dynamic weight latency 29
ospfv3 cost dynamic weight L2-factor 29

For more information on OSPF commands, refer to the following URL:
http://www.cisco.com/en/US/docs/ios/iproute_ospf/command/reference/iro_book.html

Use the following configuration guidelines for disabling split horizon in EIGRP:

By default split horizon is enabled in EIGRP. You can disable split horizon by entering the no ip split-horizon eigrp command for the respective autonomous system number.

interface vmi number
no ip split-horizon eigrp as-number
 
   

Enter the following command to disable the ip redirects on the vmi interface when you are configuring the vmi interface for EIGRP:

interface vmi number
no ip redirects

Use the following configuration guidelines for setting EIGRP values of radio link metrics:

EIGRP monitors the following metrics on an interface allowing the tuning of the EIGRP metric calculations; use the metric weights router configuration command:

metric weights tos k1 k2 k3 k4 k5
 
   

where tos denotes type of service (currently, it must always be zero) and use the following default values for weights:

k1 - 1

k2 - 0

k3 - 1

k4 - 0

k5 - 0


Note The no metric weights command restores the K-values to the defaults listed above.


Most configurations use the Delay and Bandwidth metrics with Bandwidth taking precedence.

You must set the weights identically on all routers in an autonomous system.


Note If you wish to use the default K-values you do not need to enter the metric weights command.


To set the metric dampening value for EIGRP, enter the following commands for either change-based or interval-based dampening of metric updates received through VMI:

Change Based Dampening:

ip50-1(config)#int vmi 4
ip50-1(config-if)#eigrp 100 interface dampening-change 40
 
   

Default Value for Change Based Dampening:
50%

To enable change-based dampening using the default Value, enter the following command:

eigrp 100 interface dampening-change
 
   

To disable change-based dampening, enter the following command:

no eigrp 100 interface dampening-change
 
   

Interval-based Dampening:

ip50-1(config)#int vmi 4
ip50-1(config-if)#eigrp 100 interface dampening-interval 20
 
   

Default Timer value for Interval-based Dampening:
30 seconds

To enable interval-based dampening using the default Value, enter the following command:

eigrp 100 interface dampening-interval
 
   

To disable interval-based dampening, enter the following command:

no eigrp 100 interface dampening-interval 

The following exceptions will result in an immediate update:

a down interface

a down route

any change in a metric triggered outside the scope of the VMI metric update


Note No recommended values other than default are currently available.


For more information on EIGRP commands, refer to:

http://www.cisco.com/en/US/docs/ios/iproute_eigrp/command/reference/ire_book.html

Caveats

Caveats describe unexpected behavior in Cisco IOS releases. Caveats listed as open in a prior release are carried forward to the next release as either open or closed (resolved).

This section lists caveats for the following releases:

Cisco IOS Release 15.2(1)GC2

Cisco IOS Release 15.2(1)GC1

Cisco IOS Release 15.2(1)GC

Cisco IOS Release 15.2(1)GC2

The following sections list caveats for Cisco IOS Release 15.2(1)GC2:

Open Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5915 and 5940 ESR

Open Caveats for the Cisco 5915 ESR

This section lists open caveats for the Cisco 5915 ESR running Cisco Release IOS 15.2(1)GC2:

CSCtr42899

The Cisco 5915 ESR may reboot while running a stress test with 64 byte frame size at high rate.

Workaround: There is no workaround.

CSCtq80319

The No sreloc section system message may display during boot up. This does not affect the bootup.

Workaround: There is no workaround.

CSCtn27966

When password-recovery is set to 0x1 and 0x2002 on the Cisco 5915 ESR, password recovery may become disabled.

Workaround: There is no workaround.

Closed Caveats for the Cisco 5915 and 5940 ESR

This section lists closed caveat(s) for the Cisco 5915, and 5940 ESR running Cisco Release IOS 15.2(1)GC2:

CSCtt55925

Multicast, PIM, and BSR advertisements may fail over unnumbered PPP link.

CSCtn84802

With specific IPv6 source addresses (addresses which have multicast bit set in the address(s) including IPv6 stateless autoconfig) the Cisco IOS Zone Based Firewall may not correctly inspect IPv6 flows. This causes a session through the firewall to fail.

CSCtx81439

When you create a new PPPoE session with the same IPv4 and IPv6 addresses as those in an existing running session, a logic flaw may cause VMI to detect that it is in aggregate mode. VMI then transitions to an Up/Up state.

Cisco IOS Release 15.2(1)GC1

The following sections list caveats for Cisco IOS Release 15.2(1)GC1.

Open Caveats for the Cisco 5915 and 5940 ESR

Open Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5915 ESR

Closed Caveats for the Cisco 5940 ESR

Open Caveats for the Cisco 5915 and 5940 ESR

This section lists open caveats for the Cisco 5915 and 5940 ESR running Cisco Release IOS 15.2(1)GC1:

CSCtt55925

Multicast, PIM, and BSR advertisements may fail over unnumbered PPP link.

Workaround: Use a static mroute pointing at the interface or use numbered links - or do not use PPP encapsulation.

CSCtn84802

With specific IPv6 source addresses (addresses which have multicast bit set in the address(s) including IPv6 stateless autoconfig) the Cisco IOS Zone Based Firewall may not correctly inspect IPv6 flows. This causes a session through the firewall to fail.

Workaround: There is no workaround.

CSCtx81439

When you create a new PPPoE session with the same IPv4 and IPv6 addresses as those in an existing running session, a logic flaw may cause VMI to detect that it is in aggregate mode. VMI then transitions to an Up/Up state.

Workaround: Enter the shutdown and noshutdown commands on the interface.

Open Caveats for the Cisco 5915 ESR

This section lists open caveats for the Cisco 5915 ESR running Cisco Release IOS 15.2(1)GC1:

CSCtr42899

The Cisco 5915 ESR may reboot while running a stress test with 64 byte frame size at high rate.

Workaround: There is no workaround.

CSCtq80319

The No sreloc section system message may display during boot up. This does not affect the bootup.

Workaround: There is no workaround.

CSCtn27966

When password-recovery is set to 0x1 and 0x2002 on the Cisco 5915 ESR, password recovery may become disabled.

Workaround: There is no workaround.

Closed Caveats for the Cisco 5915 ESR

This section lists closed caveats for the Cisco 5915 ESR running Cisco Release IOS 15.2(1)GC1:

CSCtr43092

Multiple stream of traffic at a very high traffic rate over a fast Ethernet interface may cause a fatal transmit error and shut down the interface.

CSCtw54984

The Cisco 5915 ESR may crash when you attempt to boot the router configuration from an external TFTP server.

CSCts78211

When flash memory does not have enough re-usable free space left, a crashinfo file is not generated during a crash. This triggers an exception to the watchdog timers.

Closed Caveats for the Cisco 5940 ESR

This section lists closed caveats for the Cisco 5940 ESR running Cisco Release IOS 15.2(1)GC1:

CSCtu86284

The SNMP manager feature is missing from the c5940-adventerprisek9-mz.SPA image.

Cisco IOS Release 15.2(1)GC

The following section lists caveats for the Cisco IOS Release 15.2(1)GC:

Open Caveats for the Cisco 5915 and 5940 ESR

Open Caveats for the Cisco 5915 ESR

Open Caveats for the Cisco 5940 ESR

Open Caveats for the Cisco 5915 and 5940 ESR

This section lists open caveats for the Cisco 5915 and 5940 ESR running Cisco Release IOS 15.2(1)GC:

CSCtt55925

Multicast, PIM and BSR advertisements may fail over unnumbered PPP link.

Workaround: Use a static mroute pointing at the interface or use numbered links - or do not use PPP encapsulation.

CSCtn84802

With specific IPv6 source addresses (addresses which have multicast bit set in the address(s) including IPv6 stateless autoconfig) the Cisco IOS Zone Based Firewall may not correctly inspect IPv6 flows. This causes a session through the firewall to fail.

Workaround: There is no workaround.

CSCtx81439

When you create a new PPPoE session with the same IPv4 and IPv6 addresses as those in an existing running session, a logic flaw may cause VMI to detect that it is in aggregate mode. VMI then transitions to an Up/Up state.

Workaround: Enter the shutdown and noshutdown commands on the interface.

Open Caveats for the Cisco 5915 ESR

This section lists open caveats for the Cisco 5915 ESR running Cisco Release IOS 15.2(1)GC:

CSCtr42899

The Cisco 5915 ESR may reboot while running a stress test with 64 byte frame size at high rate.

Workaround: There is no workaround.

CSCtq80319

The No sreloc section system message may display during boot up. This does not affect the bootup.

Workaround: There is no workaround.

CSCtn27966

When password-recovery is set to 0x1 and 0x2002 on the Cisco 5915 ESR, password recovery may become disabled.

Workaround: There is no workaround.

CSCts78211

When flash memory does not have enough re-usable free space left, a crashinfo file is not generated during a crash. This triggers an exception to the watchdog timers.

Workaround: Always have sufficient space in flash memory and delete unwanted files.

CSCtr43092

Multiple stream of traffic at a very high traffic rate over a fast Ethernet interface may cause a fatal transmit error and shut down the interface.

Workaround: There is no workaround.

CSCtw54984

The Cisco 5915 ESR may crash when you attempt to boot the router configuration from an external TFTP server.

Workaround: If it is necessary to load configuration from an external TFTP server and a crash does occur, use an EEM applet to load the configuration.

The configuration file loaded from the TFTP server will not directly configure the router. Instead, the configuration file containing EEM applets performs the actual configuration of the router after the configuration file is loaded from the TFTP server. The EEM applets are essentially entering the commands on the command line - just as a user would do when entering the commands manually.

Open Caveats for the Cisco 5940 ESR

This section lists open caveats for the Cisco 5940 ESR running Cisco IOS Release 15.2(1)GC:

CSCtu86284

The SNMP manager feature is missing from the c5940-adventerprisek9-mz.SPA image.

Workaround: There is no workaround.

Obtaining Documentation, Support, and Security Guidelines

For information on obtaining documentation, submitting a service request, and gathering additional information, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at the following URL:

http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html

Subscribe to the What's New in Cisco Product Documentation as a Really Simple Syndication (RSS) feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service. Cisco currently supports RSS Version 2.0.