Telindus 1031, User And Reference Manual

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Telindus 1031 Router Chapter 8
User manual Configuring the bridge
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8.2 The self-learning and Transparent Spanning Tree bridge
The Telindus 1031 Router features two bridging mechanisms:
• self-learning bridging,
• self-learning bridging in conjunction with the Transparent Spanning Tree (TST) algorithm, or briefly
Spanning Tree bridging.
Bridging principle Description
self-learning The bridge learns which data it has to forward to the other LAN segment and
which data it has to block. I.e. it builds its own bridging table.
In other words, you do not have to configure a bridging table with MAC
addresses of stations that are located on the separated LAN segments but that
have to be able to communicate with each other.
self-le TST This is based on the self-learning principle, but a protocol is used to implement
the TST algorithm.
Bridging loops
The primary goal of this algorithm is to avoid that bridging loops arise. A bridg-
ing loop occurs when two self-learning bridges are placed in parallel. This
results in data that keeps circling around as each bridge forwards the same
data.
The TST algorithm
Using the TST algorithm, bridges know of each others existence. By communi-
cating with each other, they establish one single path for reaching any particu-
lar network segment. If necessary, they may decide to disable some bridges in
the network in order to establish this single path.
This is a continuous process. So if a bridge fails, the remaining bridges will
reconfigure their bridging tables keeping each LAN segment reachable.