Cisco 4500 Unexpected Reboots

[abuzarghalib]

Hello all,

I have a couple of cisco 4500 switches rebooted due to single power supply failure or bounce only. Any idea? 

Thanks,

Abuzar Ghalib

[Flavio Miranda]

Hi

 If they are single power supply  and the power supply failure, then, reload is expected, no?    Power supply is not something to troubleshooting. Once we think they are not OK, best thing to do is replace it immediatly.

[abuzarghalib]

Thank you Flavio for the contribution. 

These switches has two power supplies and we replaced the bad and the bouncing ones then the switches became stable. In one case we only switch off the bad power supply and the switch became stable. 

To clear my question, why the switches rebooted although the second power supply is working fine and the load required only one power supply. 

[marce1000]

 - You need to provide logging-info's to clarify that , best is to use and configure a syslog-server as an overall log-collector, then follow-up on logs as they arrive on the syslog server, the idea being that perhaps another culprit is the cause being masked by looking at the problems with the power supplies. Also when the switch reboots issue the command show version and examine the Last reload reason.

 M.

 M.

[abuzarghalib]

Some of the switches you will see a continuous bouncing of one of the power supplies and in some only showing that one power supply get bad:

The below is example  

Jan 16 20:02:59.326 EST: %C4K_IOSMODPORTMAN-4-POWERSUPPLYBAD: Power supply 1 has failed or been turned off
Jan 16 20:03:14.369 EST: %C4K_IOSMODPORTMAN-6-POWERSUPPLYGOOD: Power supply 1 is okay

The reason in some switches show as reload and in some power-on

[marce1000]

 - Make sure the (external)  power feed to the power supply (supplies)  is regular stable and good, if not it could confuse the whole switch too. 

[balaji.bandi]

Cisco 4500 Unexpected Reboots

No one can answer this, based on the Physical situation what conditions, what were the Logs shown at that time?

Sometimes it may be a single instance due to some contact issue of PSU ?

If you have captured the Logs post here before after, we can look and help you.

If you have 2 Supervisors, you may need a higher PSU requirement, show the command of power consumption can explain.

what was the uptime of switch - before you removed PSU ?

[Georg Pauwen]

Hello,

post the output of:

show power supplies

If the info displays the below:

Power supplies needed by system:1

then make sure the redundancy mode is set to 'redundant':

4500(config)# power redundancy-mode redundant

[abuzarghalib]

The power supply need is 1 in all these switches and the redundancy-mode is configured redundant already.

[Leo Laohoo]

Post the complete output to the following commands: 

1. sh version 
2. sh logging onboard uptime detail