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ola
New Member

6500 high cpu load

Hi,

Is there any way to see what is causing the load on the cpu?

We are running a 6504 with sup720 and 12.2(18) sxf16.

The show proc cpu gives me an average of 60 - 80%, but the details only reveals 5-10. How can I see what traffic is actually causing the load?

8 REPLIES
New Member

Re: 6500 high cpu load

Hi

You can do a show proc cpu sorted to sort according to order (Highest load process on top).

You can then see the process name that is hogging CPU resources. Post the process name here if you need more help.

Most of the time it is the logging daemon hogging CPU (because of sudden increase of logs)

ola
New Member

Re: 6500 high cpu load

Yes, and add | excl 0.00 so I only get the ones actually having something other than 0.

But it only shows a few % of the total load.

Can I somehow see the rest?

New Member

Re: 6500 high cpu load

It may not be process utilisation moreso interrupt utilisation

Could you post the output of

show proc cpu sorted 1min

Also clear all your counters and do

show int | i output drops

ola
New Member

Re: 6500 high cpu load

I solved it by setting up CoPP.

That way I could find a few servers with the wrong MTU.

Changing the MTU on the servers solved our problem.

Hall of Fame Super Silver

Re: 6500 high cpu load

Hello Ola,

you have been kind to provide a feedback on this issue.

This helps to improve the forums.

CoPP by rate limiting packets sent to main CPU had helped and you have found an explanation of the problem.

Best Regards

Giuseppe

New Member

Re: 6500 high cpu load

Hi,

Can you let me know more details on "CoPP"; i am also facing similar issue like high utilization, it would be helpful to know more on this.

Regards,

Amol More.

ola
New Member

Re: 6500 high cpu load

Hi,

Sure, it is a QoS feature for traffic to the cpu, with a bonus of DOS protection.

You set it up with access-lists, class-maps and policy-maps, then bind it to the control plane with a service-policy.

The way I did it was to set it up without dropping any traffic that exceeds or violates the policy but transmit all so I wouldn't drop any traffic accidentally. You still get hits in the access-lists so that you can see where the traffic is originating from. The service policy is not needed to get hits in the access-lists, but it would give you a bonus of finding out how much traffic you have for routing, arp and so on. Make sure to add an entry for permit ip any any at the end of the access-list.

You can capture non ip traffic by matching the class-map to a protocol instead of an access-list.

Check the configuraqtion guide for your version of the IOS.

Then check the hits in the access-lists and the traffic rates with show access-list and show policy-map control-plane input.

Hope that will help you out.

/Ola

ola
New Member

Re: 6500 high cpu load

Oh, I forgot, once I figured out what ip addresses was generating the traffic i used the NAM to capture it and find out why the traffic was sent to the cpu.

But any sniffer would work for that.

/Ola

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