Upgrading the Switch Software
Finding the Software Version and Feature Set
The Cisco IOS image is stored as a bin file in a directory that is named with the Cisco IOS release. A subdirectory contains the files needed for web management. The image is stored on the system board flash device (flash:).
You can use the show version privileged EXEC command to see the software version that is running on your switch. The second line of the display shows the version.
Note Although the show version output always shows the software image running on the switch, the model name shown at the end of this display is the factory configuration and does not change if you upgrade the software license.
You can also use the dir filesystem : privileged EXEC command to see the directory names of other software images that you might have stored in flash memory.
Deciding Which Files to Use
If you have a service support contract and order a software license or if you order a switch, you receive the universal software image and a specific software license. If you do not have a service support contract, such as a SMARTnet contract, download the IP base image from Cisco.com. For Catalyst 3750-X and 3560-X switches, this image has the IP base and LAN base feature sets.
Note A Catalyst 3750-X or 3560-X switch running the LAN base feature set supports only 255 VLANs.
The switches running the universal software images can use permanent and temporary software licenses. See the “Cisco IOS Software Activation Conceptual Overview” chapter in the Cisco IOS Software Activation Configuration Guide :
The universal software images support multiple feature sets. Use the software activation feature to deploy a software license and to enable a specific feature set.
Catalyst 3750-X and 3560-X switches running payload-encryption images can encrypt management and data traffic. Switches running nonpayload-encryption images can encrypt only management traffic, such as a Secure Shell (SSH) management session.
- Management traffic is encrypted when SSH, Secure Socket Layer (SSL), Simple Network Management Protocol (SNMP), and other cryptographic-capable applications or protocols are enabled.
- Data traffic is encrypted when MACsec is enabled.
For more information about Catalyst 3750-X and 3560-X software licenses and available images, see the Cisco IOS Software Installation Document on Cisco.com:
Table 3 Software Images
Catalyst 3750-X and Catalyst 3560-X switches
Universal without payload encryption
All the supported universal image features, Kerberos, SSH, SSL, and SNMPv3
LAN base, IP base, and IP services software licenses
Universal with payload encryption
All the supported universal image features, Kerberos, SSH, SSL, SNMPv3, and MACsec
LAN base, IP base, and IP services software licenses
The upgrade procedures in these release notes describe how to perform the upgrade by using a combined tar file. This file contains the Cisco IOS image file and the files needed for the embedded device manager. You must use the combined tar file to upgrade the switch through the device manager. To upgrade the switch through the command-line interface (CLI), use the tar file and the archive download-sw privileged EXEC command.
Archiving Software Images
Before upgrading your switch software, make sure that you have archived copies of the current Cisco IOS release and the Cisco IOS release from which you are upgrading. You should keep these archived images until you have upgraded all devices in the network to the new Cisco IOS image and until you have verified that the new Cisco IOS image works properly in your network.
Cisco routinely removes old Cisco IOS versions from Cisco.com. See Product Bulletin 2863 for more information:
You can copy the bin software image file on the flash memory to the appropriate TFTP directory on a host by using the copy flash: tftp: privileged EXEC command.
Note Although you can copy any file on the flash memory to the TFTP server, it is time-consuming to copy all of the HTML files in the tar file. We recommend that you download the tar file from Cisco.com and archive it on an internal host in your network.
You can also configure the switch as a TFTP server to copy files from one switch to another without using an external TFTP server by using the tftp-server global configuration command. For more information about the tftp-server command, see the “Basic File Transfer Services Commands” section of the Cisco IOS Configuration Fundamentals Command Reference, Release 12.2 :
Upgrading a Switch by Using the Device Manager or Network Assistant
You can upgrade switch software by using the device manager or Network Assistant. For detailed instructions, click Help.
Note When using the device manager to upgrade your switch, do not use or close your browser session after the upgrade process begins. Wait until after the upgrade process completes.
Upgrading a Switch by Using the CLI
This procedure is for copying the combined tar file to the switch. You copy the file to the switch from a TFTP server and extract the files. You can download an image file and replace or keep the current image.
To download software, follow these steps:
Step 1 Use Table 3 to identify the file that you want to download.
Step 2 Download the software image file:
a. If you are a registered customer, go to this URL and log in:
b. Navigate to Switches > LAN Switches - Access
c. Navigate to your switch model.
d. Click IOS Software, and select the latest IOS release.
e. Download the image you identified in Step 1.
Step 3 Copy the image to the appropriate TFTP directory on the workstation, and make sure that the TFTP server is properly configured.
For more information, see Appendix B in the software configuration guide for this release.
Step 4 Log into the switch through the console port or a Telnet session.
Step 5 (Optional) Ensure that you have IP connectivity to the TFTP server by entering this privileged EXEC command:
Switch# ping tftp-server-address
For more information about assigning an IP address and default gateway to the switch, see the software configuration guide for this release.
Step 6 Download the image file from the TFTP server to the switch. If you are installing the same version of software that is currently on the switch, overwrite the current image by entering this privileged EXEC command:
Switch# archive download-sw /overwrite /reload tftp:[[//location]/directory]/image-name.tar
The /overwrite option overwrites the software image in flash memory with the downloaded one.
The /reload option reloads the system after downloading the image unless the configuration has been changed and not saved.
For // location, specify the IP address of the TFTP server.
For / directory / image-name .tar, specify the directory (optional) and the image to download. Directory and image names are case sensitive.
This example shows how to download an image from a TFTP server at 188.8.131.52 and to overwrite the image on the switch:
Switch# archive download-sw /overwrite tftp://184.108.40.206/c3750x-universal-tar.122-55.SE.tar
You can also download the image file from the TFTP server to the switch and keep the current image by replacing the /overwrite option with the /leave-old-sw option.
Recovering from a Software Failure
For recovery procedures, see the “Troubleshooting” chapter in the software configuration guide for this release.
Limitations and Restrictions
You should review this section before you begin working with the switch. These are known limitations that will not be fixed, and there is not always a workaround. Some features might not work as documented, and some features could be affected by recent changes to the switch hardware or software.
Note Device Classifier has been disabled by default starting from Release 15.2(2)E. Any features dependent on device classifier should enable it if required.
Access Control List
- When a MAC access list is used to block packets from a specific source MAC address, that MAC address is entered in the switch MAC-address table.
The workaround is to block traffic from the specific MAC address by using the mac address-table static mac-addr vlan vlan-id drop global configuration command. (CSCse73823)
Address Resolution Protocol
- The switch might place a port in an error-disabled state due to an Address Resolution Protocol (ARP) rate limit exception even when the ARP traffic on the port is not exceeding the configured limit. This could happen when the burst interval setting is 1 second, the default.
The workaround is to set the burst interval to more than 1 second. We recommend setting the burst interval to 3 seconds even if you are not experiencing this problem.(CSCse06827))
Cisco Transceiver Modules and SFP Modules
- Cisco GLC-GE-100FX SFP modules with a serial number between OPC0926xxxx and OPC0945xxxx might show intermittent module not valid, data, status, link-flapping, and FCS errors.
The workaround is to use modules with serial numbers that are not in the specified range. (CSCsh59585)
- When switches are installed closely together and the uplink ports of adjacent switches are in use, you might have problems accessing the SFP module bale-clasp latch to remove the SFP module or the SFP cable (Ethernet or fiber).
Use one of these workarounds:
– Allow space between the switches when installing them.
– In a switch stack, plan the SFP module and cable installation so that uplinks in adjacent stack members are not all in use.
– Use long, small screwdriver to access the latch then remove the SFP module and cable. (CSCsd57938)
- The far-end fault optional facility is not supported on the GLC-GE-100FX SFP module.
The workaround is to configure aggressive UDLD. (CSCsh70244).
- When an excessive number (more than 100 packets per second) of Address Resolution Protocol (ARP) packets are sent to a Network Admission Control (NAC) Layer 2 IP-configured member port, a switch might display a message similar to this:
PLATFORM_RPC-3-MSG_THROTTLED: RPC Msg Dropped by throttle mechanism: type 0, class 51, max_msg 128, total throttled 984323
-Traceback= 6625EC 5DB4C0 5DAA98 55CA80 A2F2E0 A268D8
No workaround is necessary. Under normal conditions, the switch generates this notification when snooping the next ARP packet. (CSCse47548)
- When there is a VLAN with protected ports configured in fallback bridge group, packets might not be forwarded between the protected ports.
The workaround is to not configure VLANs with protected ports as part of a fallback bridge group. (CSCsg40322)
When a switch port configuration is set at 10 Mb/s half duplex, sometimes the port does not send in one direction until the port traffic is stopped and then restarted. You can detect the condition by using the show controller ethernet-controller or the show interfaces privileged EXEC commands.
The workaround is to stop the traffic in the direction in which it is not being forwarded, and then restart it after 2 seconds. You can also use the shutdown interface configuration command followed by the no shutdown command on the interface. (CSCsh04301)
- When line rate traffic is passing through a dynamic port, and you enter the switchport access vlan dynamic interface configuration command for a range of ports, the VLANs might not be assigned correctly. One or more VLANs with a null ID appears in the MAC address table instead.
The workaround is to enter the switchport access vlan dynamic interface configuration command separately on each port. (CSCsi26392)
- (Catalyst 3750-X or 3560-X switches) When the switch flash memory has less than 6 MB free space, there is not enough space in flash memory to hold temporary files created as part of a microcontroller unit (MCU) image upgrade, and the upgrade fails.
The workaround is to delete any unnecessary files in flash memory, delete the temporary files created as part of the failed upgrade, and try the MCU upgrade again. (CSCtd75400)
- (Catalyst 3750-X or 3560-X switches) When you enter the test cable-diagnostics tdr interface or the show cable-diagnostics tdr interface privileged EXEC command on an interface to determine the length of a connected cable, the cable length might be reported as N/A. This can occur when there is no link, a 10 Mb/s link, or a 100 Mb/s link, even though there are no cable faults. Cable length is reported correctly when a 1 Gb/s link is active on the interface.
The workaround to verify the cable length is to enter the commands when a Gigabit link is active on the interface or after disconnecting the far end of the cable. (CSCte43869)
- In an EtherChannel running Link Aggregation Control Protocol (LACP), the ports might be put in the suspended or error-disabled state after a stack partitions or a member switch reloads. This occurs when:
– The EtherChannel is a cross-stack EtherChannel with a switch stack at one or both ends.
– The switch stack partitions because a member reloads. The EtherChannel is divided between the two partitioned stacks, each with a stack master.
The EtherChannel ports are put in the suspended state because each partitioned stack sends LACP packets with different LACP Link Aggregation IDs (the system IDs are different). The ports that receive the packets detect the incompatibility and shut down some of the ports. Use one of these workarounds for ports in this error-disabled state:
– Enable the switch to recover from the error-disabled state.
– Enter the shutdown and the no shutdown interface configuration commands to enable the port.
The EtherChannel ports are put in the error-disabled state because the switches in the partitioned stacks send STP BPDUs. The switch or stack at the other end of the EtherChannel receiving the multiple BPDUs with different source MAC addresses detects an EtherChannel misconfiguration.
After the partitioned stacks merge, ports in the suspended state should automatically recover. (CSCse33842)
- When a switch stack is configured with a cross-stack EtherChannel, it might transmit duplicate packets across the EtherChannel when a physical port in the EtherChannel has a link-up or link-down event. This can occur for a few milliseconds while the switch stack adjusts the EtherChannel for the new set of active physical ports and can happen when the cross-stack EtherChannel is configured with either mode ON or LACP. This problem might not occur with all link-up or link-down events.
No workaround is necessary. The problem corrects itself after the link-up or link-down event. (CSCse75508)
- The switch might display tracebacks similar to this example when an EtherChannel interface port-channel type changes from Layer 2 to Layer 3 or the reverse:
15:50:11: %COMMON_FIB-4-FIBNULLHWIDB: Missing hwidb for fibhwidb Port-channel1 (ifindex 1632) -Traceback= A585C B881B8 B891CC 2F4F70 5550E8 564EAC 851338 84AF0C 4CEB50 859DF4 A7BF28 A98260 882658 879A58
There is no workaround. (CSCsh12472)
IEEE 802.1x Authentication
- If a supplicant using a Marvel Yukon network interface card (NIC) is connected an IEEE 802.1x-authorized port in multihost mode, the extra MAC address of 0c00.0000.0000 appears in the MAC address table.
Use one of these workarounds (CSCsd90495):
– Configure the port for single-host mode to prevent the extra MAC address from appearing in the MAC address table.
– Replace the NIC card with a new card.
- When MAC authentication bypass is configured to use Extensible Authentication Protocol (EAP) for authorization and critical authentication is configured to assign a critical port to an access VLAN:
– If the connected device is supposed to be unauthorized, the connected device might be authorized on the VLAN that is assigned to the critical port instead of to a guest VLAN.
– If the device is supposed to be authorized, it is authorized on the VLAN that is assigned to the critical port.
Use one of these workarounds (CSCse04534):
– Configure MAC authentication bypass to not use EAP.
– Define your network access profiles to not use MAC authentication bypass. For more information, see the Cisco Access Control Server (ACS) documentation.
- When IEEE 802.1x authentication with VLAN assignment is enabled, a CPUHOG message might appear if the switch is authenticating supplicants in a switch stack.
The workaround is not use the VLAN assignment option. (CSCse22791)
- Multicast packets with a time-to-live (TTL) value of 0 or 1 are flooded in the incoming VLAN when all of these conditions are met:
– Multicast routing is enabled in the VLAN.
– The source IP address of the packet belongs to the directly connected network.
– The TTL value is either 0 or 1.
The workaround is to not generate multicast packets with a TTL value of 0 or 1, or disable multicast routing in the VLAN. (CSCeh21660)
- Multicast packets denied by the multicast boundary access list are flooded in the incoming VLAN when all of these conditions are met:
– Multicast routing is enabled in the VLAN.
– The source IP address of the multicast packet belongs to a directly connected network.
– The packet is denied by the IP multicast boundary access-list configured on the VLAN.
There is no workaround. (CSCei08359)
- Reverse path forwarding (RPF) failed multicast traffic might cause a flood of Protocol Independent Multicast (PIM) messages in the VLAN when a packet source IP address is not reachable.
The workaround is to not send RPF-failed multicast traffic, or make sure that the source IP address of the RPF-failed packet is reachable. (CSCsd28944)
- If the clear ip mroute privileged EXEC command is used when multicast packets are present, it might cause temporary flooding of incoming multicast traffic in the VLAN.
There is no workaround. (CSCsd45753)
- When you configure the ip igmp max-groups number and ip igmp max-groups action replace interface configuration commands and the number of reports exceed the configured max-groups value, the number of groups might temporarily exceed the configured max-groups value. No workaround is necessary because the problem corrects itself when the rate or number of IGMP reports are reduced. (CSCse27757)
- When you configure the IGMP snooping throttle limit by using the ip igmp max-groups number interface configuration on a port-channel interface, the groups learned on the port-channel might exceed the configured throttle limit number, when all of these conditions are true:
– The port-channel is configured with member ports across different switches in the stack.
– When one of the member switches reloads.
– The member switch that is reloading has a high rate of IP IGMP joins arriving on the port-channel member port.
The workaround is to disable the IGMP snooping throttle limit by using the no ip igmp max-groups number interface configuration command and then to reconfigure the same limit again. (CSCse39909)
PoE or PoE+
- When a loopback cable is connected to a switch PoE port, the show interface status privileged EXEC command shows not connected, and the link remains down. When the same loopback cable is connected to a non-PoE port, the link becomes active and then transitions to the error-disabled state when the keepalive feature is enabled.
There is no workaround. (CSCsd60647)
- The Cisco 7905 IP Phone is error-disabled when the phone is connected to an external power source.
The workaround is to enable PoE and to configure the switch to recover from the PoE error-disabled state. (CSCsf32300)
- The pethPsePortShortCounter MIB object appears as short even though the powered device is powered on after it is connected to the PoE port.
There is no workaround. (CSCsg20629)
- (Catalyst 3750-X or 3560-X switches) When a powered device (such as an IP phone) connected to a PoE+ port restarts and sends a CDP or LLDP packet with a power TLV, the switch locks to the power-negotiation protocol of that first packet. The switch does not respond to power requests from the other protocol. For example, if the switch is locked to CDP, it does not provide power to devices that send LLDP requests. If CDP is disabled after the switch has locked on it, the switch does not respond to LLDP power requests and can no longer power on any accessories.
The workaround is to turn the powered device off and then on again.
- When QoS is enabled and the egress port receives pause frames at the line rate, the port cannot send packets.
There is no workaround. (CSCeh18677)
- Egress shaped round robin (SRR) sharing weights do not work properly with system jumbo MTU frames.
There is no workaround. (CSCsc63334)
- In a hierarchical policy map, if the VLAN-level policy map is attached to a VLAN interface and the name of the interface-level policy map is the same as that for another VLAN-level policy map, the switch rejects the configuration, and the VLAN-level policy map is removed from the interface.
The workaround is to use a different name for the interface-level policy map. (CSCsd84001)
- If the ingress queue has low buffer settings and the switch sends multiple data streams of system jumbo MTU frames at the same time at the line rate, the frames are dropped at the ingress.
There is no workaround. (CSCsd72001)
- When you use the srr-queue bandwidth limit interface configuration command to limit port bandwidth, packets that are less than 256 bytes can cause inaccurate port bandwidth readings. The accuracy is improved when the packet size is greater than 512 bytes.
There is no workaround. (CSCsg79627)
- If QoS is enabled on a switch and the switch has a high volume of incoming packets with a maximum transmission unit (MTU) size greater than 1512 bytes, the switch might reload.
Use one of these workarounds:
– Use the default buffer size.
– Use the mls qos queue-set output qset-id buffers allocation1... allocation4 global configuration command to allocate the buffer size. The buffer space for each queue must be at least 10 percent. (CSCsx69718) (Catalyst 3750-X switches)
- If you configure a large number of input interface VLANs in a class map, a traceback message similar to this might appear:
01:01:32: %BIT-4-OUTOFRANGE: bit 1321 is not in the expected range of 0 to 1024
There is no impact to switch functionality.
There is no workaround. (CSCtg32101)
- When configuring queuing policy, the sum of the queuing buffer should not exceed 100%.
- RADIUS change of authorization (COA) reauthorization is not supported on the critical auth VLAN.
There is no workaround. (CSCta05071)
- The switch stack might reload if the switch runs with this configuration for several hours, depleting the switch memory and causing the switch to fail:
– The switch has 400 Open Shortest Path First (OSPF) neighbors.
– The switch has thousands of OSPF routes.
The workaround is to reduce the number of OSPF neighbors to 200 or less. (CSCse65252)
- When the PBR is enabled and QoS is enabled with DSCP settings, the CPU utilization might be high if traffic is sent to unknown destinations.
The workaround is to not send traffic to unknown destinations. (CSCse97660)
- When upgrading switches in a stack, the director cannot send the correct image and configuration to the stack if all switches in the stack do not start at the same time. A switch in the stack could then receive an incorrect image or configuration.
The workaround is to use an on-demand upgrade to upgrade switches in a stack by entering the vstack download config and vstack download image commands. (CSCta64962)
- When you upgrade a Smart Install director to Cisco IOS Release 12.2(55)SE but do not upgrade the director configuration, the director cannot upgrade client switches.
When you upgrade the director to Cisco IOS Release 12.2(55)SE, the workaround is to also modify the configuration to include all built-in, custom, and default groups. You should also configure the tar image name instead of the image-list file name in the stored images. (CSCte07949)
- Backing up a Smart Install configuration could fail if the backup repository is a Windows server and the backup file already exists in the server.
The workaround is to use the TFTP utility of another server instead of a Windows server or to manually delete the existing backup file before backing up again. (CSCte53737)
- If the director in the Smart Install network is located between an access point and the DHCP server, the access point tries to use the Smart Install feature to upgrade even though access points are not supported devices. The upgrade fails because the director does not have an image and configuration file for the access point.
There is no workaround. (CSCtg98656)
- When a Smart Install director is upgrading a client switch that is not Smart Install-capable (that is, not running Cisco IOS Release 12.2(52)SE or later), the director must enter the password configured on the client switch. If the client switch does not have a configured password, there are unexpected results depending on the software release running on the client:
– When you select the NONE option in the director CLI, the upgrade should be allowed and is successful on client switches running Cisco IOS Release 12.2(25)SE through 12.2(46)SE, but fails on clients running Cisco IOS Release 12.2(50)SE through 12.2(50)SEx.
– When you enter any password in the director CLI, the upgrade should not be allowed, but it is successful on client switches running Cisco IOS Release 12.2(25)SE through 12.2(46)SE, but fails on clients running Cisco IOS Release 12.2(50)SE through 12.2(50)SEx.
There is no workaround. (CSCth35152)
SPAN and RSPAN
- When the RSPAN feature is configured on a switch, CDP packets received from the RSPAN source ports are tagged with the RSPAN VLAN ID and forwarded to trunk ports carrying the RSPAN VLAN. When this happens, a switch that is more than one hop away incorrectly lists the switch that is connected to the RSPAN source port as a CDP neighbor.
This is a hardware limitation. The workaround is to disable CDP on all interfaces carrying the RSPAN VLAN on the device connected to the switch. (CSCeb32326)
- When egress SPAN is running on a 10-Gigabit Ethernet port, only about 12 percent of the egress traffic is monitored.
There is no workaround. This is a hardware limitation. (CSCei10129)
- (Catalyst 3560-X and 3750-X switches) When you enter the show monitor privileged EXEC command the monitor source port output is incorrect. This situation occurs only if the monitor source port(s) is a pluggable Gigabit module and you set any source port combination, except when just using a single Gigabit port on the pluggable module as the source port.
This is a cosmetic issue and the workaround is to use the show platform monitor session privileged EXEC command to display the correct source ports. (CSCtn67868)
Spanning Tree Protocol
When a switch or switch stack running Multiple Spanning Tree (MST) is connected to a switch running Rapid Spanning Tree Protocol (RSTP), the MST switch acts as the root bridge and runs per-VLAN spanning tree (PVST) simulation mode on boundary ports connected to the RST switch. If the allowed VLAN on all trunk ports connecting these switches is changed to a VLAN other than VLAN 1 and the root port of the RSTP switch is shut down and then enabled, the boundary ports connected to the root port move immediately to the forward state without going through the PVST+ slow transition.
There is no workaround.
Stacking (Catalyst 3750-X Switch Stack only)
- When a switch stack is running 802.1x single host mode authentication and has filter-ID or per-user policy maps applied to an interface, these policies are removed if a master switchover occurs. Even though the output from the show ip access-list privileged EXEC command includes these ACLs, the policies are not applied.
The workaround it to enter a shutdown and then a no shutdown interface configuration command on the interface. (CSCsx70643)
- When using the logging console global configuration command, low-level messages appear on both the stack master and the stack member consoles.
The workaround is to use the logging monitor global configuration command to set the severity level to block the low-level messages on the stack member consoles. (CSCsd79037)
- If a new member switch joins a switch stack within 30 seconds of a command to copy the switch configuration to the running configuration of the stack master, the new member might not get the latest running configuration and might not operate properly.
The workaround is to reboot the new member switch. Use the remote command all show run privileged EXEC command to compare the running configurations of the stack members. (CSCsf31301)
- When the flash memory of a stack member is almost full, it might take longer to start up than other member switches. This might cause that switch to miss the stack-master election window. As a result, the switch might fail to become the stack master even though it has the highest priority.
The workaround is to delete files in the flash memory to create more free space. (CSCsg30073)
- A stack member switch might fail to bundle Layer 2 protocol tunnel ports into a port channel when you have followed these steps:
1. You configure a Layer 2 protocol tunnel port on the master switch.
2. You configure a Layer 2 protocol tunnel port on the member switch.
3. You add the port channel to the Layer 2 protocol tunnel port on the master switch.
4. You add the port channel to the Layer 2 protocol tunnel port on the member switch.
After this sequence of steps, the member port might stay suspended.
The workaround is to configure the port on the member switch as a Layer 2 protocol tunnel and at the same time also as a port channel. For example:
Switch(config)# interface fastethernet1/0/11
Switch(config-if)# l2protocol-tunnel cdp
Switch(config-if)# channel-group 1 mode on (CSCsk96058)
- After a stack bootup, the spanning tree state of a port that has IEEE 802.1x enabled might be blocked, even when the port is in the authenticated state. This can occur on a voice port where the Port Fast feature is enabled.
The workaround is to enter a shutdown interface configuration command followed by a no shutdown command on the port in the blocked state. (CSCsl64124)
- When the switch stack is in the HSRP active state and a master changeover occurs, you cannot ping the stack by using an HSRP virtual IP address.
There is no workaround. (CSCth00938)
- In a stackable switch, if VRF configuration is changed and this is followed by a master switchover, VRF stops working.
The workaround is to reload the switch stack after the VRF configuration is changed. (CSCtn71151)
Stack Power (Catalyst 3750-X only)
- When a power stack has been configured in redundant mode, which is not the default, and then split by either removing cables or disabling StackPower ports, the newly created power stack has the same mode as the former power stack, but this is not shown in the configuration file.
The workaround when you are forming power stack topologies if the power stack mode is not the default (power sharing), you should also configure the power stack mode on the new power stacks by entering the mode redundant power-stack configuration command. (CSCte33875)
- If the number of VLANs times the number of trunk ports exceeds the recommended limit of 13,000, the switch can fail.
The workaround is to reduce the number of VLANs or trunks. (CSCeb31087)
- When the domain is authorized in the guest VLAN on a member switch port without link loss and an Extensible Authentication Protocol over LAN (EAPOL) is sent to an IEEE 802.1x supplicant to authenticate, the authentication fails. This problem happens intermittently with certain stacking configurations and only occurs on the member switches.
The workaround is to enter the shut and no shut interface configuration commands on the port to reset the authentication status. (CSCsf98557)
- The error message %DOT1X_SWITCH-5-ERR_VLAN_NOT_FOUND might appear for a switch stack under these conditions:
– IEEE 802.1 is enabled.
– A supplicant is authenticated on at least one port.
– A new member joins a switch stack.
You can use one of these workarounds:
– Enter the shutdown and the no shutdown interface configuration commands to reset the port.
– Remove and reconfigure the VLAN. (CSCsi26444)
- When you enter the boot host retry timeout global configuration command to specify the amount of time that the client should keep trying to download the configuration and you do not enter a timeout value, the default value is zero, which should mean that the client keeps trying indefinitely. However, the client does not keep trying to download the configuration.
The workaround is to always enter a non zero value for the timeout value when you enter the boot host retry timeout timeout-value command. (CSCsk65142)
- When many VLANs are configured on the switch, high CPU utilization occurs when many links are flapping at the same time.
The workaround is to remove unnecessary VLANs to reduce CPU utilization when many links are flapping. (CSCtl04815)
The following guidelines and limitations apply to configuring Cisco TrustSec SGT and SGACL on the Catalyst 3750-X switch:
- You cannot statically map an IP-subnet to an SGT. You can only map IP addresses to an SGT. When you configure IP address-to-SGT mappings, the IP address prefix must be 32.
- If a port is configured in Multi-Auth mode, all hosts connecting on that port must be assigned the same SGT. When a host tries to authenticate, its assigned SGT must be the same as the SGT assigned to a previously authernticated host. If a host tries to authenticate and its SGT is different from the SGT of a previously authenticated host, the VLAN port (VP) to which these hosts belong is error-disabled.
- Cisco TrustSec enforcement is supported only on up to eight VLANs on a VLAN-trunk link. If there are more than eight VLANs configured on a VLAN-trunk link and Cisco TrustSec enforcement is enabled on those VLANs, the switch ports on those VLAN-trunk links will be error-disabled.
- The switch cannot assign an SGT based on SXP listening; it can only forward the SXP bindings through the SXP protocol.
- Port-to-SGT mapping should be configured only on Cisco TrustSec links (that is, switch-to-switch links).
When port-to-SGT mapping is configured on a port, an SGT is assigned to all ingress traffic on that port. There is no SGACL enforcement for egress traffic on the port.
- SGT/SGACL is supported on Cisco Catalyst 3750-X and 3560-X series switches with all network uplink modules: C3KX-NM-1G, C3KX-NM-10G, C3KX-NM-10GT and C3KX-SM-10G. The C3KX-SM-10G is only required for MACsec on the uplinks.
- TrustSec Layer-3 Identity Port Mapping (L3IPM) is not supported on Catalyst 3750-X and 3560-X series switches.
IP SLA Video Operation
- After removing an IP SLA Video Operation VRF configuration, the VRF configuration still shows up in show running-config and show ip sla configuration. The VRF configuration is removed, but the CLI is not updated.
The workaround is to completely remove the IP SLA Video Operation and configure again without VRF. (CSCuf39077)
Device Manager Limitations
- When you are prompted to accept the security certificate and you click No, you only see a blank screen, and the device manager does not launch.
The workaround is to click Yes when you are prompted to accept the certificate. (CSCef45718)
C3KX-SM-10G Network Module
- NetFlow Data Export (NDE) fails when the IP address specified by the destination keyword belongs to a network that is connected to the Ethernet management port (FastEthernet0) on the switch.
There is no workaround. (CSCtt05810)
- Cisco Trust Security (CTS) MACsec cannot be configured on the C3KX-SM-10G service module until the POST test has been completed. Wait approximately 45 seconds after the module is inserted before you configure CTS MACsec on the port. (CSCuc20819)