Cisco 7206VXR router High CPU Due to Interrupts

[Mohammed Asif C Y]

Hi,

   We have Cisco 7206VXR router running High CPU due to interrupts. Need help to analyze the interrupt traffic. There is no CEF drops, observed clear switching. But still reason is unknown.

Let me know what command output will give us the clear picture of interrupt traffic.

CPU utilization for five seconds: 88%/68%; one minute: 68%; five minutes: 66%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process 
   1          28       194        144  0.00%  0.00%  0.00%   0 Chunk Manager    
   2      166364    986382        168  0.00%  0.00%  0.00%   0 Load Meter       
   3           0         1          0  0.00%  0.00%  0.00%   0 chkpt message ha 
   4           0         1          0  0.00%  0.00%  0.00%   0 EDDRI_MAIN       
   5    13444832    738616      18202  0.00%  0.16%  0.12%   0 Check heaps      

Regards

MAC

[Riyas V M]

Hi Mac,

The Cisco 7200 Series supports process switching, fast switching, and Cisco Express Forwarding (CEF), but does not support any form of distributed switching(hardware switching). The main CPU in the NPE performs all the switching tasks.

The performance of the router is based on the type of NPE you use on the router.

Please refer the PDF link below for the same.

http://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf

High cpu due to interrupt on 7200 Routers would be mainly due to high traffic, please get the below outputs from the router to identify the same.

*         Show proc cpu sort | exc 0.00

*         Show int | in line | rate | drops --------> Execute this command about 10-15 times in quick succession

*         Show ip traffic

*         Show cef not

*         Show cef int

*         Show ip int

HTH

Riyas

[Joseph W. Doherty]

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Posting

"Interrupt" CPU is where the CPU normally records fast packet forwarding.  As Riyas has noted, normally this CPU usage will correspond with high traffic load (although "high" traffic load depends on the nature of the traffic, your configuration, and how "fast" a NPE you have).

I.e. your high interrupt CPU might just be reflecting the forwarding capacity of your 7200.

PS:

Hmm, what you might also want to investigate is why there's 20% of non-interrupt CPU.