High CPU (IP Input) on 3620

[phil_carter]

Hello,

Receiving high CPU bursts (rising to 80% at a time) due to high IP Input (after performing sh proc cpu) for example:

31 4032252 2192903 1838 24.82% 16.58% 17.43% 0 IP Input

The router has a single 3750 switch stack and 2 WAN links out, none of which are passing any large amount of traffic (10m link using c.5-10% util; 2m link using c.1%;100m LAN using c.1%).

Question is, what can be causing these frequent but intermittent high CPU bursts? There is only one OSPF area configured, but not running CEF.

Any advice would be appreciated.

thanks

Phil

[vijayasankar]

Hi,

Have a look at the following URLs which might be helpful to diagnose.

Troubleshooting High Cpu utilisation in IP Input.

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af3.shtml#req

Performance Tuning Basics.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00800a7306.shtml

-VJ

[phil_carter]

Thanks - I've added cef for now to see if this has an impact.