High CPU due to interrupts on ISR 3925

[Sohan Lal]

Hi,

can anyone suggest what is the reason for high CPU due to interrupts?

Cisco3925#sh proc cpu sorted
CPU utilization for five seconds: 99%/96%; one minute: 98%; five minutes: 96%
 PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process
   2      922280     6367334        144  2.34%  0.46%  0.40%   0 Load Meter      
   3     7053880      149337      47234  1.05%  0.98%  1.00%   0 FNF Cache Ager P
 198    86582696   106182560        815  0.24%  0.42%  0.41%   0 Skinny Msg Serve
   6    84273436     6686241      12604  0.24%  0.18%  0.20%   0 Check heaps     
 480    12983276     2509415       5173  0.16%  0.08%  0.07%   0 SNMP Traps      
 374     3278312     5617721        583  0.16%  0.10%  0.08%   0 CFT Timer Proces
 450    13815392    45106788        306  0.16%  0.06%  0.05%   0 DSMP            
 393       15104         855      17665  0.16%  0.03%  0.00% 645 SSH Process     
 477    51951564    21414781       2425  0.16%  0.70%  0.49%   0 SNMP ENGINE     

thanks for your support

Sohan

[Philip D'Ath]

That's easy.  The router has got more forwarding load than it can handle.

You can only do two things:

• Reduce the amount of traffic being forwarded by the router
• Get a more powerful router/switch.

[Sohan Lal]

Thank you Philip

So you saying router is not capable enough to handle the load? however I checked somewhere in the Cisco website that this model of router (Cisco CISCO3925) router can handle the traffic up to 500 mbps, please correct me if I am wrong.

is the only solution to get high router? we have 80 Mbps WAN circuit on the router and as soon as it goes up to 70 Mbps we started facing high CPU issue. we have two router at site of same version.

thanks for your help.

Sohan

[Philip D'Ath]

Is this mostly small packets, like VoIP?

[Sohan Lal]

We do have voice traffic on it, but not sure how to find how much traffic of VoIP on it. Just a question, I observed interrupts on even CPU is normal, I mean if CPU is 20% in this case intrrupts are 17%, 20%/17%, so I am surprised why this is the case, is there anything related switching method wrongly configured, however I can see CEF is enable and working on router.

Thanks,