[Contents]
[Prev]
[Next]
[Index]
[Report an Error]
Bridges and Switches
Bridges and switches combine LAN segments into a single Ethernet
network by using multiple ports to connect the physical wires in each
segment. Although bridges and switches are fundamentally the same,
bridges generally provide more management and more interface ports.
As Ethernet packets flow through a bridge, the bridge tracks the source
MAC address of the packets and stores the addresses and their associated
input ports in an interface table. As it receives subsequent packets,
the bridge examines its interface table and takes one of the following
actions:
- If the destination address does not match an address in
the interface table, the bridge transmits the packet to all hosts
on the network using the Ethernet broadcast address.
- If the destination address maps to the port through which
the packet was received, the bridge or switch discards the packet.
Because the other devices on the LAN segment also received the packet,
the bridge does not need to retransmit it.
- If the destination address maps to a port other than the
one through which the packet was received, the bridge transmits the
packet through the appropriate port to the corresponding LAN segment.
[Contents]
[Prev]
[Next]
[Index]
[Report an Error]
