[c-nsp] Cisco 3750 High CPU

[Phil Mayers]

On 04/07/2010 08:55 PM, Chris Lane wrote:
> sh spanning-tree
>
> No spanning tree instance exists.

It's almost certainly a loop somewhere, based on what you posted:

CPU util for five seconds: 99%/27%; one minute: 95%; five minutes: 92%
  PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
  251     2985921     15274     195490 39.29% 11.05%  6.01%   0 hulc

You could try enabling spanning tree ;o)

Or the various, tedious other ways to find loops (look at port 
packets/sec, trace back to adjacent device, repeat until edge port 
found). Broadcast storm control might help, but is pretty useless 
unfortunately in my experience.