–
VLAN 1 is mapped to MSTI 1.
–
VLAN 2 and VLAN 3 are mapped to MSTI 2.
–
Other VLANs are mapped to MSTI 0.
l
Regional root
Regional roots are classified into Internal Spanning Tree (IST) and MSTI regional roots.
In the region B0, C0, and D0 on the network shown in
, the switching devices
closest to the Common and Internal Spanning Tree (CIST) root are IST regional roots.
An MST region can contain multiple spanning trees, each called an MSTI. An MSTI
regional root is the root of the MSTI. On the network shown in
, each MSTI has
its own regional root.
Figure 8-3
MSTI
Root
VLAN
10&20&30
VLAN1
0&20
VLAN 20&30
VLAN
10&30
VLAN30
VLAN
10&30
VLAN20
VLAN 10
MST Region
Root
MSTI
corresponding to
VLAN 10
Root
MSTI
corresponding to
VLAN 20
MSTI
corresponding to
VLAN 30
MSTI links
MSTI links blocked by the protocol
MSTIs are independent of each other. An MSTI can correspond to one or more VLANs,
but a VLAN can be mapped to only one MSTI.
l
CIST root
On the network shown in
, the CIST root is the root bridge of a CIST. The CIST
root is a device in A0.
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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