User`s guide

3-2
Configuring
Figure 3-1. Typical Bridging Application
Bridges regulate network traffic on the basis of the source and
destination addresses that are in each data packet. Bridges are
protocol-transparent, meaning they can handle different types of
traffic regardless of the network protocol, for example, IP and IPX.
A bridge reads the source and destination address of every data
packet it receives and from this information determines where to
send the packet.
An important capability of a bridge is its ability to recognize and
ignore local traffic. Local traffic refers to data packets that only
need to travel within one network segment. For example, a
message transmitted from workstation A to workstation C in
Figure 3-1 does not need to leave LAN 1. The bridge connected to
LAN 1 sees all traffic from LAN 1, including LAN 1 local traffic.
But from the source and destination address of each packet, the
bridge determines if a packet is local.
If a packet is local, the bridge does not forward it. By forwarding
only packets addressed to devices on other segments, bridges
reduce unnecessary traffic and thereby enhance the overall
performance of the internetwork.
A
B
C
LAN 1
LAN 2
LAN 3