Chapter 13 Spanning Tree Protocol
GS2210 Series User’s Guide
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Figure 102
STP/ RSTP Net w ork Ex am ple
Wit h MSTP, VLANs 1 and 2 ar e m apped t o different spanning t r ees in t he net wor k. Thus t raffic fr om
t he t w o VLANs t ravel on differ ent pat hs. The follow ing figur e show s t he net wor k exam ple using
MSTP.
Figure 103
MSTP Net w or k Exam ple
13.10.2 MST Region
An MST r egion is a logical gr ouping of m ult iple net w or k devices t hat appear s as a single device t o
t he r est of t he net w ork. Each MSTP- enabled device can only belong t o one MST r egion. When
BPDUs ent er an MST r egion, ext er nal pat h cost ( of pat hs out side t his r egion) is incr eased by one.
I nt er nal pat h cost ( of pat hs w it hin t his r egion) is incr eased by one w hen BPDUs t raver se t he r egion.
Devices t hat belong t o t he sam e MST r egion ar e configur ed t o have t he sam e MSTP configurat ion
ident ificat ion set t ings. These include t he follow ing param et er s:
•
Nam e of t he MST region
•
Revision level as t he unique num ber for t he MST r egion
A
B
VLAN 1
VLAN 2
A
B
VLAN 1
VLAN 2
