Bridges Figure 6 79 Bridges Operate at the
Bridges
Figure 6. 79
Bridges • Operate at the data link layer • Also use backward learning in recording source address on transmissions • Unlike repeaters, bridges will not forward a frame onto another LAN segment if it knows about location of destination node • Bridge management gets more complicated when loops are possible in the frame route.
Network Bridge LLC MAC MAC Physical Figure 6. 80
S 1 S 2 S 3 LAN 1 LAN 2 port 1 B 1 Address port 2 Port S 5 S 4 LAN 3 port 1 B 2 Address port 2 Port Figure 6. 81
S 1 S 2 S 3 S 5 S 4 S 5 LAN 1 LAN 2 B 1 port 1 Address S 1 port 2 Port 1 LAN 3 B 2 port 1 Address S 1 port 2 Port 1 Figure 6. 82
S 1 S 2 S 3 LAN 1 S 2 LAN 2 B 1 port 2 S 5 S 4 LAN 3 B 2 port 1 port 2 Address Port S 1 S 3 1 2 S 1 S 3 1 1 Figure 6. 83
S 1 S 2 S 3 S 4 LAN 1 LAN 2 B 1 port 1 Address S 1 S 3 S 4 port 2 Port 1 2 2 S 5 S 4 S 3 LAN 3 B 2 port 1 port 2 Address Port S 1 S 3 S 4 1 1 2 Figure 6. 84
S 1 S 2 S 3 S 2 S 5 S 4 S 1 LAN 2 port 1 Bridge 1 port 2 LAN 3 port 1 Bridge 2 port 2 Address Port S 1 S 3 S 4 S 2 1 2 2 1 S 3 S 4 1 1 2 Figure 6. 85
LAN 1 (1) B 1 B 2 (2) LAN 2 (1) (2) B 3 (3) (2) (1) B 4 (2) LAN 3 (1) B 5 (2) LAN 4 Figure 6. 86
Figure 6. 87
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