HIGH CPU 4500X UTILIZATION

[Derek Mayabi]

Hello Support

Please inform me on how to prevent high cpu ulization on a cisco device. An example is a cisco 4500X switch with a sample of the configs shown below.

BRM_HQ_CSW_01#sh proc cpu sort

Core 0: CPU utilization for five seconds: 1%; one minute: 4%; five minutes: 23%

Core 1: CPU utilization for five seconds: 99%; one minute: 70%; five minutes: 56%

PID   Runtime(ms) Invoked uSecs 5Sec     1Min     5Min     TTY   Process

8418   120346     280131   429   49.94   36.36   28.11  0     iosd             

11263 106         1028     103   0.08     0.04     0.18     0     oom_poll.sh     

11803 3644       33795   107   0.08     0.79     8.19     0     ffm 

This high utilization has prevented the 4500x switch from issueing Ip addresses( It acts as the organizations DHCP server)

[Reza Sharifi]

Hi,

This maybe an IOS bug.  You need to open a ticket with TAC and send them this output, so they can help you.

HTH

[Steve Fuller]

Hi Derek,

Take a read of the forum post cisco 4510R+E high cpu utilization on one core and note the link to DoS attack with MAC-Address (K5 L2 Hardware Addre process).

I'm not suggesting you necessarily have a DoS attack, but do you see MAC address flapping?

Regards

[InayathUlla Sharieff · Accepted solution]

Derek,

1- Below you can find a simple guide to troubleshoot on the most common causes of high CPU in the 4500 platform just in case you need it for future reference.

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

2- Kindly check in the logs if there are any logs pointing to any routing protocols flaps/ HSRP flaps/MAC addres flaps?

3- If any issues see when the routes are unreachalbe refer the following bug :CSCua99861 (

High CPU identified attributed to L3 Glean packets coming in from a couple of print servers sending packets to unknown destinations and after shutting them down, the CPU had dropped down).

4-Further more to determine the root cause we would need the following information:

- show version, show module

- show process cpu history

- show processes cpu sorted

- show processes cpu detailed process iosd sorted

- show platform health

- show platform cpu packet statistics

- show platform cpu packet statistics all

- show platform cpu packet buffered

- show ip traffic

HTH

Regards

Inayath

*Plz rate all usefull posts.

[Erik Molenaar]

Hi Derek,

Glad your problem is solved, but what exactly turned out to be the problem?

Thanks,

Erik

[ibrahimbadr4669]

Hi Derek,

what's the root cause of the high utilization