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Catalyst 8510C performace/CEF and 802.1q sub-interfaces

I have a 8510C used as a Collapsed Core switch and ideally I want to trunk a couple of VLANs from an edge switch to the 8510C. I do this using sub-interfaces and dot1q encapsulation. All the setup is fine and works, BUT the performace is terrible, I assume CEF is being bypassed and everything is being process-switched. If I remove the sub-interfaces and just use the major interface (i.e. fastethernet 0/0/0) then everything works fine, as soon as a sub-interface is added and the encapsulation is set to dot1q performance dies. I am routing to another physical interface off the 8510C (fastethernet 1/0/0), so its not an issue of sending the data up and down the same trunk.

Is this a limitation of the 8510C or is there something I have missed? IOS version is 12.1(20)E, but this happened with 12.1(19)E and 12.1(13)Ex.


New Member

Re: Catalyst 8510C performace/CEF and 802.1q sub-interfaces

This more looks like a compatability issue, not sure though...

Re: Catalyst 8510C performace/CEF and 802.1q sub-interfaces

I'll open a TAC case then........