High CPU utilization on CAt 6500 and 4000

[Manjunatha Jayaram]

Hi

I have cisco 6500 and cisco 4000 switches in my network.

These switches are showing high cpu utilization.

The Cisco 4000 switch is showing some 53% utilization while Cisco 6500 is showing 40% utilization.

The major contributor for catalyst 4000 utilization is :

SynCOnfig

PacketForwarding

SwitchingOverhead snd

Admin Overhead

The major contributor for 6500 utilization is:

SptBpduTx

Is this normal or something wrong in the network??

Let me know.

rds

[glen.grant]

Cat 4000 will run 25-30 percent with nothing configured or running it may not be that high ,though I haven't seen a 4000 that high in our network except when the slammer worm hit . Cat 6000 seems high , it would have to be passing an awful lot of traffic to push it that high . We used them in our core and i have never seen them above 10 percent and our network is big , fortune 500 company . If spanning tree is the major contributor you should look at pruning off vlans that don't need to be on each access layer switch as each vlan has it 's own spanning tree and this will drive your utilization up .

[czisimides]

Are you using any form of bridging, such as irb ?

On our Cat4000s we had bridge irb accidently enabled on several ports, this pushed the CPU utilization to 75 - 80%. once we swithced it off of these ports utilization dropped to 35 - 40%.