switch and bridge mac port table question

[osmany]

First question: When the system is first started, when PC1 sends data to PC6, what happens to the MAC-port tables of Switch 1, Bridge and Switch 2?  

Second question: When all the tables have completed the learning process, what will be the MAC port addresses of Switch 1, Switch 2 and Bridge?

[Joseph W. Doherty]

For 1st question:

A switch, or bridge (actually a switch is multi port bridge), will note a ingress frame's source MAC and the ingress port.  It will update, as necessary, its MAC/port table.

It will also consult its MAC/port table for the frame's destination MAC.  If a match is found, it will transmit the frame on the port for that MAC.  If destination MAC not found, it will transmit the frame on all its ports except the ingress port (NB: if VLANs are being used, ingress and egress ports have to be within the same VLAN.)

For 2nd question:

Depends on what has transpired to that point in time.  The above answer explains the learning and forwarding processes.  The only thing to add, the MAC/port table ages entries.  I.e. every like ingress refreshes that entry's timeout, but if the entry does timeout, it's removed from the MAC/port table.  (NB: There's no standard for the timeout value and manageable devices may allow you to change the default timeout used by that device.  [Usually, the Cisco timeout default is 300 seconds.].)