Cisco Catalyst 4000 series Hardware Troubleshoot page 17

The show version command provides software version information to use for a bug search. For
example, if you identify an exception in the show log command output, use the Bug Toolkit in order
to search for bugs on the Catalyst 4000 and the exception. Also, the show version command gives
you a quick snapshot of how long the switch has been up. For example:
Uptime is 28 days, 11 hours, 42 minutes
The show test 0 command output indicates an F status on the supervisor or module if any of the
diagnostics failed. An improperly seated module can cause the switch to crash. If the supervisor or
module shows failed, proceed with the troubleshooting steps in the System component LEDs are
orange/red or supervisor not online section of this document.
The show logging buffer 1023 command displays all system messages, which includes possible error
messages that can relate to the crash. See the Getting system error messages section for
troubleshooting suggestions.
2. Issue the show commands and troubleshooting procedures in the preceding steps first. If these steps
fail, capture the show tech−support command output. This command displays output for all these
commands continuously, which means the output continues to scroll until complete or until the
display is ended with the Ctrl + C keystrokes:
sh version, sh flash, sh microcode, sh system, sh module, sh port, sh Mac, sh trunk, sh vlan, sh
vtp domain, sh spantree active, sh spantree summary, sh test, sh arp, sh ip route, sh cdp
neighbor detail, sh netstat stats, show memory buffers, show out−of−band stats, sh inband stats,
show cam static, sh cam count dynamic, sh cam system, sh config, sh log, sh proc, sh proc mem,
sh proc CPU, ps, Ps −c
Often, the output from all these commands is not necessary to resolve a specific problem, so TAC
engineers cannot ask for it. But, it is beneficial to have this output should other show commands or
troubleshooting steps fail to resolve the problem.
3. Should all the previous troubleshooting steps fail to diagnose the problem, capture these hidden
commands, as well as the other commands in the previous steps, and open a case with the Cisco
Technical Support:
♦
ps−c (capture multiple times)
♦
show mbuf all (hidden)
♦
show nvramenv 1 (hidden)
♦
show interposition 1 (hidden)
These are hidden commands, which means they cannot be parsed with a "?" and you cannot Tab to
complete. Type the command out in its entirety. This output can or cannot be useful in the resolution
of your case. These commands are undocumented, and therefore the TAC engineer is not required to
explain the output to the customer.
Misleading Problems
There are many misleading problems that are thought to be caused by faulty hardware. This section lists a few
issues that are often confused as a hardware failure.
•
One common customer issue is for the system LED to show faulty when additional power supplies
are added, but not plugged in. When this happens, both the ps#−status and sys−status shows faulty.
This is because the switch senses an additional power supply is installed but is not active. Since this
can also mean that the additional power supply has actually failed, an onsite inspection is required.
•
A common misconception when you view output of the show proc cpu command is that the Kernel
and Idle percentage is interpreted to be the CPU utilization for that time period. The Kernel and Idle is
the percentage of CPU that was idle for that time frame.