what is cpu used for on switch

[carl_townshend]

Hi all, as most switching is done using asic chips, what is the main reason for cpu on a switch ?

[Joseph W. Doherty]

"Control plane" processing.

[carl_townshend]

can you give me an example?

how about mac learning ? is this done initially by the control plane processor ?

[Joseph W. Doherty]

An example? Sure, device processing a received broadcast packet (as a host).

[carl_townshend]

i see, is there anything else, what about mac learning etc, is this done by asic ?

[Joseph W. Doherty]

"anthing else" - sure other control plane functions.

"mac learning", probably depends on switch architecture.