Allied Telesis AT-S26 - Manual (Page 145)

145
Appendix B
Spanning Tree Protocol Concepts
This appendix provides a brief explanation of the Spanning Tree
Protocol as implemented by Allied Telesyn on the switches.
For detailed information on the operation of the Spanning Tree
Protocol, consult Section 4 of IEEE Std 802.1D, ISO/IEC 10038: 1993.
The AT-9006 switch, which runs the AT-S26 software, implements
the IEEE 802.1D Spanning Tree Protocol (STP). The STP provides a
network with robustness and allows network administrators to easily
change their network topology. Its implementation reduces complex
network topologies (networks with multiple paths between source
and destination nodes) to a single active topology. This technique
guarantees that loops do not occur between source and destination
nodes of the network. Loops are eliminated by placing some of the
redundant ports in a “blocking” state, in which they do not forward
packets but continue to execute the protocol. If the network
topology changes, for example by the failure, removal, or addition of
an active network node, a “blocked” port may be included in the new
active topology and begin forwarding frames.