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High CPU Utilization


Dear All,

I am facing an issue since last 15 days. We are using Cisco 3845 with 2 ISP. One for data another for VOIP.

We have 2 VOIP servers on cloud. We are doing Policy Based routing that any traffic destined for VOIP servers will go via 1st ISP and all other traffic is going via 2nd ISP via default route.

The issue is with IP Input. It is causing high CPU utilization.

We have to restart the router daily after 24 hours, after restarting router work fine for a day. And if you don't restart it after 24 hours, the IP Input Process take too much CPU utilization that caused too much cpu utilization. Due to this voice packets start dropping and distortion etc.

Can someone please help me regarding this?

3 Replies 3



post the configuration of the 3845...


Make sure the access lists used for PBR do not contain any 'deny' statements, as these cause packets being sent straight to the CPU...

Joseph W. Doherty
Hall of Fame
Hall of Fame
If the issue grows worse over time, and is "fixed" with a reboot, you might have some form of memory leak or little excess RAM to begin with. For the former what's the router model and IOS being used? Of the latter, what's your free RAM stats after the reboot and right before you need to restart?

Leo Laohoo
Hall of Fame
Hall of Fame
What is the WAN speed?
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