High VLAN Interface utilization (6500/sup720)

[jrhofman]

Can anyone tell me why a VLAN interface would show 100% utilization for a givin VLAN? This is a sup720 we're talking about.

I understand that the bandwidth of a virtual interface is 1Gig but I thought this was more related to routing metric.

Users were actually seeing performance issues until we changed how the servers on this particular interface were replicating. Once we did this the VLAN interface utilization went down and performance went up.

It doesn't make sense to me that the VLAN interface would limit the actual throughput of the various ports that are mapped to it. Throughput should be related to the switch module 61xx, 65xx, 67xx and how it interfaces to the backplan and the backplan speed itself.

Any insights would be helpful......

[jv]

Can you please post a "show version" as well as a "show run interface VlanXXX" where XXX is the interface in question.

[glen.grant]

If the layer 3 SVI was showing 100% that means it had a lot of traffic that was being layer 3 processed switched instead of hardware switched . Normally most traffic is hardware switched within the ASICS and never even gets passed up to that layer . What would cause this I'm not sure .