Spanning Tree Algorithm - TRENDnet TE100-S14 User Manual

Spanning Tree Algorithm

The TE-100/S14 Switch implements the Spanning Tree Algorithm
(henceforth STA) to provide the following functions:
•
Network loop detection and prevention - There can be
only one path between any two bridged Ethernet LAN
1
segments . If there are more than one path, forwarded
packets may loop indefinitely. STA detects any looped path
and selects the path with the lowest "path cost" as the active
path, while blocking the other paths.
•
Automatic topology re-configuration - If an active path
fails and there is a backup path, the backup path will be
automatically activated, and the STA will automatically re-
configure the network topology.
The detailed Algorithm is defined in the STA Specification. The
following introduces the key information and terminology needed
to interpret the parameters used in the TE-100/S14 Switch that
support the STA. It is also helpful to understand the effects of
changing these parameters. Appendix B lists the defaults setting
used by the TE-100/S14 Switch.
STA operates at two levels, the Bridge
In addition, STA uses several timers to periodically ensure the
integrity of the Bridges and their ports in a network.
1
A shared hub is a star topology cabling implementation of the same
LAN segment, therefore, is not a Bridge.
2
Bridge is the standard terminology used in the Spanning Tree
Algorithm Specification, which could be a bridge or switch.
2
level and the Port level.
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