[c-nsp] 3550 High CPU - nothing in proc cpu

[Hector Herrera]

Great, so now I know:

from 'show ip cef switching stat' I learned that there is a large
number of packets with an expired TTL (TTL-expired is handled by the
IP process, ie. software routing)

from 'show interface switching' (hidden command) I learned the
interface that has a high number of packets In and packets Out in the
row "IP Process"

Since the number of packets in the two commands above are very close
to each other, I think I have identified the network interface with
the large number of TTL-expired packets.  It is a BGP interface, so my
best guess is that a BGP neighbour is advertising routes that they
don't actually carry in their routing tables and for some reason they
are sending the packets back to me, and the question now is to locate
the culprit route advertisement and contact the neighbor.  Right?

Still, for the next time I see high cpu usage, the commands to use are:

'show process cpu' and look at the first few lines to determine if
it's interrupts or processes consuming the cpu time.  If it's
processes, look at the list of processes for any that are using large
percentages.

To diagnose high cpu consumption by interrupts, CPU Profiling
(http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af0.shtml)
is a possible tool.

Thank you all for your help!

Hector