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MSTP basic concepts
Figure 315 Basic concepts in MSTP
Assume that all devices in Figure 315 are running MSTP. This section explains some basic concepts
of MSTP.
MST region
A multiple spanning tree region (MST region) consists of multiple devices in a switched network and
the network segments among them. These devices have the following characteristics:
• All are MSTP-enabled.
• They have the same region name.
• They have the same VLAN-to-instance mapping configuration.
• They have the same MSTP revision level configuration.
• They are physically linked with one another.
For example, all the devices in region A0 in Figure 315
have the same MST region configuration.
• The sa
me region name.
• The same VLAN-to-instance mapping configuration (VLAN 1 is mapped to MSTI 1, VLAN 2 to
MSTI 2, and the rest to the common and internal spanning tree (CIST or MSTI 0).
• The same MSTP revision level (not shown in the figure).
Multiple MST regions can exist in a switched network. You can assign multiple devices to the same
MST region.