High CPU utilization on Catalyst 4507

[brunolucca]

Hi there,

I have a Cisco Catalyst 4507 and supervisor engine IV. The CPU utilization goes up to 99% during most part of the day. I have made some troubleshooting but I found nothing wrong. The performance of the traffic forwarding was not afected. But sometimes the switch doesn't even respond the ping.

Any idea?

Bruno

[ankbhasi]

Hi Bruno,

It can be critical too. Can you confirm if you have lot of multicast application running?

Can you check "sh proc cpu" and see whic process is hitting the CPU high?

Do you see some led lights flickering very quickly? Any log messages related to spanning tree?

Ankur

[brunolucca]

Ankur,

Check this weird results:

98 278363184 198984580 1398 34.34% 28.87% 29.21% 0 PIM Process

26 39588723324269125694 927 15.33% 17.24% 17.04% 0 Cat4k Mgmt HiPri

27 2514771002338343066 107 31.70% 27.52% 23.35% 0 Cat4k Mgmt LoPri

Make sense?

I'll attach the results of sho proc cpu

[Martin Parry]

Hi Bruno

Please can you post the output of a show platform health command?

The Mgt Hi-Priority and MGT Lo-Priority are two processes that the cat 4500 platform code runs.

I would like to see if the high cpu is down to the K2CpuMan Review process.

Regards

Martin

[brunolucca]

Martin,

As peer your request, follow the sho platform health output.

Check it out please.

[mahmoodmkl]

Hi

from the above output u can see that PIM process is taking 34% of cpu.I think its related to multicast traffic.check the multicast issues.

Thanks

Mahmood

[rafa_lanna]

Bruno,

Sometimes, it could be a software bug. There are some process that runs too frequently and uses all free CPU cycles. Once this condition occurs, the process does not recover, and constant high CPU is seen.

If the output of the 'show platform health' command shows that the RkiosPortMan Port Re process is using all of the free CPU, it could be a IOS bug problem. I've been through the same problem in a customer.

What is your IOS version?

Regards,

Rafael Lanna

[brunolucca]

Rafael,

The IOS is 12.2(19)EWA1. Could be a problem?

[rafa_lanna]

Well, I suggest you upgrade your software.

There is a bug in softwares like your. The bug is CSCeh08768.

If you have the opportunity, upgrade your sofware to Cisco IOS Software Release 12.2(25)EWA2 or later versions.

There are some TAC cases related to this problem. See this one and check if it helps.

http://www.ciscotaccc.com/lanswitching/showcase?case=K36445307

Regards,

Rafael Lanna

[amit-singh]

Hi,

I would not suggest you to upgrade the IOS directly. First please have a look at the following link and try troubleshooting any known issues regarding the same. I have used it a number of times and believe me its really good link.

http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a00804cef15.shtml

You can upgrade the IOS only in 1 case if you want to mirror/montior the CPU queues and to see the unwanted traffic hitting the CPU which is upported in 12.25SG release.

HTH,Please rate if it does.

-amit singh