Spanning tree protocol entity (stpe) – EXP Computer PathBuilder S200 User Manual

Page 90

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Bridging

Spanning Tree Protocol Entity (STPE)

Spanning Tree Protocol Entity (STPE)

Introduction

The Spanning Tree Protocol Entity (STPE) is part of the PathBuilder S200 series
switch Source Route Bridge functionality. The parameters that control Spanning
Tree Protocol operation are in the Bridge Record and Bridge Link Record. In the
Bridge Record, the STPE Control parameter setting determines whether Automatic
or Manual Spanning Tree is used.

For detailed information about the parameters in the Bridge Record and in the Bridge
Link Record, refer to the “Bridge Parameters” and “Bridge Link Parameters
sections earlier in this guide.

Automatic
Spanning Tree

Automatic Spanning Tree is dynamic and involves more parameters that enable and
control the Spanning Tree Protocol messages that communicate between the bridges.
By processing these messages, the bridges automatically determine a spanning tree
for the network. These messages are continually updated so the spanning tree
automatically adjusts to the current topology. These messages consume a small
amount of the bandwidth. The automatic version is redundant since PathBuilder
S200 series switch has the capability of re-autocalling the destination, thereby
rerouting over another link.

Manual Spanning
Tree

Manual Spanning Tree is static and cannot adjust to bridge network topology
changes. However, the process is more straightforward and does not consume
network bandwidth (no Hello frames are used). The Spanning Tree is manually
configured on a bridge link basis using the Bridge Link “STPE Link State”
parameter (FORWARD/BLOCK).

What You Need to
Configure

When you configure a node for bridging operation, the spanning tree parameters that
appear on the Bridge Parameters Record and Bridge Link Record depend on whether
you configure manual or automatic spanning tree.

Note

All bridges in a network must operate in the same mode, either all automatic or
all manual.

Custom Software
Key

One Custom Software Key (CSK) enables both the Source Route Bridging and the
Spanning Tree Protocol Entity.

Configuration

Menu

STPE Control= AUTO

STPE Control = MANUAL

Bridge Record

STPE Control = Auto

Bridge Priority

Max Age

Hello Time

Forward Delay

STPE Control = Manual

Bad Hello Threshold

Bad Hello Count

Bridge Link
Record

STPE Priority

STPE Path Cost

STPE Link State

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