switch learning

[carl_townshend]

hi all, just a quick question, what exactly does a switch do when you plug your pc in, does it add the mac address to its mac table, and check for spanning tree ? also if my pc cant find a mac address its looking for, does it automatcially get sent out of the uplink port ?

[Sureshdank]

Carl,

Whenever you plugin a PC into LAN, the switch goes from different modes i.e.

Initially it will in Disabled mode, then blocking mode, then listening mode, then learning mode and then it goes to forwarding mode.

If you configure spanning tree portfast command then it directly goes to forwarding mode.

Regards,

Suresh