Huawei AR3200 Series - Page 233

l MSTI 1 uses S4 as the root switching device to forward packets of VLAN 2.
l MSTI 2 uses S6 as the root switching device to forward packets of VLAN 3.
Devices within the same VLAN can communicate with each other and packets of different
VLANs are load-balanced along different paths.
Basic MSTP Concepts
l MST region
An MST region contains multiple switching devices and network segments between them.
The switching devices have the following characteristics:
– MSTP-enabled
– Same region name
– Same VLAN-to-instance mapping
– Same MSTP revision number
A LAN can comprise several MST regions that are directly or indirectly connected. You
can use MSTP configuration commands to group multiple switching devices into an MST
region.
As shown in Figure 8-2, the MST region D0 contains the switching devices S1, S2, S3,
and S4. The region has three MSTIs.
Figure 8-2 MST region
D0
S1
other VLANs MSTI0
S2
S4
S3
VLAN1 MSTI1
VLAN2,VLAN3 MSTI2
MSTI1
root switch:S3
MSTI2
root switch:S2
MSTI0 (IST)
root switch:S1
AP1
Master Bridge
l VLAN mapping table
The VLAN mapping table is an attribute of the MST region. It describes mappings between
VLANs and MSTIs.
Figure 8-2 shows the VLAN mapping table of the MST region D0:
Huawei AR3200 Series Enterprise Routers
Configuration Guide - LAN 8 MSTP Configuration
Issue 02 (2012-03-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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