H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 179)

22-10
Basic MSTP Terminologies
Figure 22-4 illustrates basic MSTP terms (assuming that MSTP is enabled on every device in this
figure).
Figure 22-4 Basic MSTP terminologies
MST region
A multiple spanning tree region (MST region) comprises multiple physically-interconnected
MSTP-enabled devices and the corresponding network segments connected to these devices. These
devices have the same region name, the same VLAN-to-MSTI mapping configuration and the same
MSTP revision level.
A switched network can contain multiple MST regions. You can group multiple devices into one MST
region by using the corresponding MSTP configuration commands.
As shown in Figure 22-4 , all the devices in region A0 are of the same MST region-related configuration,
including:
z
Region name
z
VLAN-to-MSTI mapping (that is, VLAN 1 is mapped to MSTI 1, VLAN 2 is mapped to instance 2,
and the other VLANs are mapped to CIST.)
z
MSTP revision level (not shown in Figure 22-4 )
MSTI
A multiple spanning tree instance (MSTI) refers to a spanning tree in an MST region.
Multiple spanning trees can be established in one MST region. These spanning trees are independent
of each other. For example, each region in
Figure 22-4 contains multiple spanning trees known as
MSTIs. Each of these spanning trees corresponds to a VLAN.
VLAN mapping table
A VLAN mapping table is a property of an MST region. It contains information about how VLANs are
mapped to MSTIs. For example, in
Figure 22-4 , the VLAN mapping table of region A0 is: VLAN 1 is