How to do debugging on Cisco router 3600?

[shayv]

Hi

I use a Cisco router 3600 that get 99% cpu from time to time (average of once a day), the only thing that recover the router is reset.
normally it gets 30% cpu.

I can see a lot of errors on eth 0/1, input and output.

I need some ideas how to debug it and to find from which interface and which IP overload it.

Thanks ahead

Shayv