High CPU Utilization in Cisco 2900 router

[Raja_D]

Hi, 

There is frequent high utilization noticed on Cisco 2900 router which is in our network. Currently I am able to login to the router without any issues but the utilization is getting nearer to 80% sometimes. 

What are the possible reasons which are resulting in High CPU utilization issue ? How much CPU utilization can generally be considered as normal ? 

Can someone guide as of how to overcome this high CPU utilization and what are the necessary steps to be followed to bring down the utilization to normal  ? Does this resolution steps can be done during Business hours or Non business hours in the network ?

Please advise.....

[james.buchanan1]

I've seen different causes to this. Are you using this router only as a router, or for voice services or some other application?

1. Upon increasing the bandwidth on a WAN circuit delivered via Ethernet handoff, I have seen this happen. For example, one customer had 2811 routers then tried to route 50mbit fiber through that router. That was beyond the supported throughput for that router.

2. IOS bugs can cause this issue. Does a reboot cause the sympton to go away?

3. Enabled debugs can cause this issue. Do a "show debug" and see if any debugging is turned on that shouldn't be.

[Raja_D]

This router is being used for call centre purpose and we have the voice services in place with two 100 MB P2P links connected to it. 

we did not go with reboot option as its in Production environment. However, its noticed that the utilization drops itselves to normal without any intervention, while debugs is not enabled on the router. 

on this 100 MB link utilization hardly goes to nearly 60 MB throughput sometimes. Does this still lead to utilization issues? How much can be considered as normal throughput over this Cisco 2900 router ?