Cisco Catalyst 5000 Series Switches

Field Notice: 'show flash' or 'show tech-support' Commands Do Not Yield the Processor to Some Protocol Processes on Supervisor IIG & IIIG

Updated November 2, 2001

October 17, 2001

Products Affected




Catalyst 5500/5000 Supervisor IIG


Catalyst 5500/5000 Supervisor IIIG

Problem Description

Executing a show flash or show tech command in a Catalyst 5500 switch with IIG or IIIG supervisor modules will fail to yield the CPU on the supervisor module to other running processes. These commands can adversely effect processes that require periodic "hellos".

Process similar to spanning tree may see spanning tree reconfigured and reconverged, while unidirectional link detection (UDLD) may incorrectly disable a port.


Only Catalyst 5500 with supervisor IIG or IIIG running Catalyst software 5.4(1) to 6.1.(2), and 6.2(1) may be effected by this problem after show flash or show tech has been issued.

  • The following spanning tree messages may be seen during the time the show flash command is executing on an adjacent switch:

    2001 Apr 21 21:16:08 eastern -04:00 %SPANTREE-7-MSGAGEEXPIRY: Msg Age timer expired on port 1/2 in vlan 1 2001 Apr 21 21:16:08 eastern -04:00 %SNMP-5-NEWROOTTRAP:New Root Trap for Vlan [1]

  • Unidirectional Link Detection may show the following:

    2001 Apr 30 09:34:24 eastern -05:00 %UDLD-3-AGGRDISABLE:Neighbor(s) of port 1/1 disappeared on bidirectional link. Port disabled.

For additional information on the problem please view the DDTS CSCdt94706 listed below.

Problem Symptoms

Potential interrupted connectivity due to spanning tree reconvergence, or ports disabled due to unidirectional link detection on Catalyst 5500 switches with supervisor IIG or IIIG.



  1. Avoid executing the show flash or show tech commands in Catalyst 5500 switches with IIG or IIIG supervisors running software 5.4(1) to 6.1(2), or 6.2(1).

  2. Raise the spanning tree maximum age to 40 and the UDLD message interval to 30.

The following Catalyst 5500 IIG and IIIG supervisor software releases fix this problem:

Note:?You must be a registered user and you must be logged in to download software.

CatOS 5.5(10) - Available on (registered customers only)

CatOS 6.1(3) - Available on (registered customers only)

CatOS 6.2(2)- Available on (registered customers only)

The following example demonstrates how to use SNMP to download a new image to the system:

snmpset -c private . octetstring
snmpset -c private . octetstring cat5000-supg.5-5-8.bin
snmpset -c private . integer 1
snmpset -c private . integer 4

Use the following example to check the status of the SNMP download:

snmpget -c private .


To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.



CSCdt94706 (registered customers only)

BPDUs not sent during filesys commands.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: