2.2 Transparent Bridging
nTransparent bridges
operate in ‘‘promiscuous’’ mode. I.e., they
read in every frame that is sent on each LAN attached to
its ports (note they do not forward every frame!).
nBridges ‘‘learn’’ where
destinations are and build up a routing table -> backwards learning algorithm.
nThe bridge maintains the
routing table that maps MAC addresses onto outgoing ports by adding,
updating and deleting addresses as time goes by.