when switches flood trafic ?

[longN]

i just wonder:
switch broadcast any fram wich destination mac address
is not in switch'es address table but did it broadcast
a frame wich source MAC is not in the table but the destination is?

 

[Jsteve]

No it will not broadcast, when the packet arrives it will add the source mac address to the table and because the destination address is all ready in the Mac address table,
it will be forwarded out the proper port.

 

[hexn]

A switch will never broadcast a frame unless it is a broadcast or a multicast. If it receives a packet whos destination is not in its mac table, it will arp for the destination, then AFTER it receives a reply, it will record it in the mac table, and send the frame out the correct port.

Kapeesh?

 

[Henrry]

Shnypr,
I think switch will forward all "unknown" packet to all ports."unknown" means destination is not in its mac table.
I think switch won't arp for the destination.

 

[hexn]

henrry is right, switches only arp when the switch itself originates the traffic, otherwise it floods the packet out all ports.

http://www.howstuffworks.com/lan-switch4.htm