Val:~$ whoami

I am Val Glinskiy, network engineer specializing in data center networks. TIME magazine selected me as Person of the Year in 2006.

Search This Blog

Tuesday, May 11, 2010

Catching high CPU usage

Suddenly your router stops responding and forwarding traffic, you can telnet into it, response on the console is very slow. Few minutes later everything is back to normal and only "show process cpu history" shows that CPU was at 100% for some time, but what caused it remains a mystery. To catch a process(es) that might have contributed to the problem, add following command in global configuration mode:

process cpu threshold type process rising 70 interval 5 falling 30 interval 5

It will generate syslog message every time CPU usage exceeds 70% for 5 or more seconds and falls below 30%. For example:

May 10 23:50:23.146 EDT: %SYS-1-CPURISINGTHRESHOLD: Threshold: Process CPU Utilization(Total/Intr): 74%/26%, Top 3 processes(Pid/Util): 192/46%, 7/1%, 2/0%

Process id 192 contributed 46%. Let's see:

Router#sho proc cpu sor | i ^_192
192   904947881922327784 47 0.00% 0.18% 0.19% 0 IP Input

 It was "IP Input" which is responsible for process-switching IP packets. Now we have something to work with and can start troubleshooting.


  1. Thank you very much for the great and with detailed example explanation. Can i ask you, if needed, some more questions as to what each command does. in the furuter

  2. I think this is a better than average article. You make this data intriguing and locks in. You give perusers a considerable measure to consider and I welcome that sort of composing. Learn more

  3. Its an incredible joy perusing your post.Its brimming with data I am searching for and I want to post a remark that "The substance of your post is magnificent" Great work.  maggiori informazioni

  4. Your post is very helpful to get some effective tips to reduce weight properly. You have shared various nice photos of the same. I would like to thank you for sharing these tips. Surely I will try this at home. Keep updating more simple tips like this.  besuche die Website