EDS-408A/405A Series User’s Manual

Featured Functions

yLocate and then disable less efficient paths (i.e., paths that have a lower bandwidth).

yEnable one of the less efficient paths if the most efficient path fails.

The figure below shows a network made up of three LANs separated by three bridges. Each segment uses at most two paths to communicate with the other segments. Since this configuration can give rise to loops, the network will overload if STP is NOT enabled.

LAN 1Bridge B
Bridge A

LAN 2

Bridge C

LAN 3

If STP is enabled, it will detect duplicate paths and prevent, or block, one of them from forwarding traffic. In the following example, STP determines that traffic from LAN segment 2 to LAN segment 1 should flow through Bridges C and A as this path has a greater bandwidth and is therefore more efficient.

LAN 1

Bridge B

Bridge A

LAN 2

Bridge C

LAN 3

What happens if a link failure is detected? As shown in next figure, the STP process reconfigures the network so that traffic from LAN segment 2 flows through Bridge B.

3-22