Spanning Tree Protocol (Stp); Spanning Tree Groups - Nortel 8300 User Manual

26 VLANs, Spanning Tree, and Static Link Aggregation

Spanning Tree Protocol (STP)

The operation of the Spanning Tree Protocol (STP) is defined in the IEEE
Std 802.1D. The Spanning Tree Protocol detects and eliminates logical
loops in a bridged or switched network. When multiple paths exist, the
spanning tree algorithm configures the network so that a bridge or switch
uses only the most efficient path. If that path fails, the protocol automatically
reconfigures the network to make another path become active, thus
sustaining network operations. You can control path redundancy for VLANs
by implementing the panning Tree Protocol (STP).
A network can include multiple instances of STP. The collection of ports in
one spanning tree instance is called a spanning tree group (STG).
This section includes the following topics:
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Spanning tree groups

Each STG consists of a collection of ports that belong to the same instance
of the STP protocol. These STP instances are completely independent
from each other (for example, they send their own BPDUs, they have their
own timers, and so on).
Multiple STGs are possible within the same switch; that is, the routing switch
can participate in the negotiation for multiple spanning trees.
Figure 4 "Multiple spanning tree groups" (page 27)
tree groups.
Configuration — VLANs, Spanning Tree, and Static Link Aggregation using Device Manager
Copyright © 2005-2007, Nortel Networks
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"Spanning tree groups" (page 26)
"Spanning Tree modes" (page 28)
"Spanning Tree FastStart" (page 28)
"Understanding STGs and VLANs" (page 28)
"Spanning Tree Protocol topology change detection" (page 29)
Nortel Ethernet Routing Switch 8300
NN46200-510 03.01 Standard
4.0 27 August 2007
shows multiple spanning