Spanning Tree Introduction: STP, RSTP, MSTP
©2008 Allied Telesis Inc. All rights reserved.
18.12
AlliedWare Plus
TM
Operating System Software Reference C613-50003-00 REV E
Software Version 5.2.1
MSTP Regions
An MST region is a set of interconnected switches that all have the same values for the
following MST configuration identification elements:
■
MST configuration name - the name of the MST region
■
Revision level - the revision number of configuration
■
Configuration Digest - the mapping of which VLANs are mapped to which MST instances
Each of the MST instances created are identified by an MSTI number. This number is locally
significant within the MST region. Therefore, an MSTI will not span across MST regions.
Figure 18-2: MSTIs in different regions
MSTI1
MSTI2
MSTI3
MSTI_
num
bers
MSTI1
MSTI3
MSTI2
MSTI4
Region 1
Region 3
Region 2
The MSTI1 in Region 1 is unrelated to the MSTI1 in Region 3. Similarly, the MSTI2 in Region 1 is quite
unrelated to the MSTI2 in Region 2.
Physical connections