Router CPU usage goes high!

[dattx_fis2]

My company has ~400 users. I use a 2801 router to route traffic between vlans ('cause we just have some layer 2 catalysts and this router) and nat for internet access. Our network model looks like this: IPS -> Router -> users. On subinterfaces, I've already used:

no ip redirects

no ip unreachables

no ip proxy-arp

But the cpu usage still goes high around 70~80%.

Do u have any ideas to reduce the cpu usage?

[Justin Brenton · Accepted solution]

Hi dattx_fis2,

Is the 2801 being used for IP phones as well?

Have you turned off all debugging?

Try this

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a00800a70f2.shtml

HTH, Please rate if so.

Regards,

Justin

[dattx_fis2]

Tks Justin.

All debbing are turned off and we don't use IP phones. I think the traffic load is so high and maybe some PCs have virus. I'm going to change the interrupt request timer by changing scheduller allocate command

[a.alekseev]

show the output

#sh proc cpu sorted 5min

or

#sh proc cpu | e 0\.00

#sh ip traffic

[a.alekseev]

show the configuration

[dattx_fis2]

I think I find the reason: I use both netflow and snmp on the router, snmp traps send to 2 mgmt servers. The router is polled too often so the cpu usage goes high