layer 3 switching methods

[arash.ne199011]

hello everyone

I'm new in ccnp routing and switching and I have many question about them

here is my question

does layer 3 switch have cut through forwarding packet or not

does layer 3 switch  have anything new in routing and forwarding

I read a document 2 days ago and it said the traditional Multi layer switch is CEF

then what is the new one?

the only thing I know is that the CEF is the newest thing In MLS forwarding and routing the packet in in detail in reference -----> switch engine and topology based is traditional

is it true ?

thanks

[Richard Burts]

Here are my comments about your questions.

Cut through forwarding was used in layer 2 forwarding. It does not apply to layer 3 forwarding.

I am not sure what you really mean about whether layer 3 switch has anything new in routing. There are always enhancements being made about the forwarding processing. Especially for layer 3 switches many of these enhancements are made in the ASIC.

We need to be careful about what you mean by traditional Multi layer switch. If we go back far enough there was no CEF and a Multi layer switch would not be using it. As CEF was developed and enhanced Cisco has included that logic in layer 3 switches. Perhaps what you are looking for in the newer one might be Distributed CEF?

HTH

Rick

[Joseph W. Doherty]

I read a document 2 days ago and it said the traditional Multi layer switch is CEF

Interesting, is this document publicly available?

"Traditional" MLS routed the first packet of the flow and switched all the subsequent packets of the flow.