Appendices | 289 |
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In all other respects, spanning tree bridges operate in the same fashion as simple learning bridges.
A Simple Bridging Example
Backbone
Port0 Net
WorkstationA
Local Net
Port1 Net
BridgeWorkstationB
WorkstationC
Bridging Example
In the diagram above, the bridge develops a table by listening to both the Port 0 net and the Port 1 net. Through the listening process, it associates Worksta- tion A with Port 0 and Workstations B and C with Port 1. A simplified bridging table is shown below:
A
B
C
When a packet with A as a destination address arrives at Port 0, the packet is dropped (A is on the same interface). When a packet with a destination address of C arrives at Port 0, the packet is forwarded to Port 1. When a packet with a destination address which isn’t in the table (or a broadcast address) arrives at Port 1, it is forwarded to Port 0.
Multiport Bridges/Switches and “Bridge Groups”
When a router has multiple interfaces, and also supports bridging/switching, some new concepts are required to understand the organization of the avail- able functions.
