Configuring MST region-related parameters (especially the VLAN mapping table) results in spanning tree recalculation and network topology jitter. To reduce network topology jitter caused by the configuration, MSTP does not recalculate spanning trees immediately after the configuration; it does this only after you perform one of the following operations, and then the configuration can really takes effect:

z

z

Activate the new MST region-related settings by using the active region-configurationcommand Enable MSTP by using the stp enable command

Two devices belong to the same MST region only when they have the same MST region name, VLAN mapping table, and MSTP revision level.

Configuration example

#Configure an MST region, with the name being “info”, the MSTP revision level being level 1, VLAN 2 through VLAN 10 being mapped to spanning tree instance 1, and VLAN 20 through VLAN 30 being mapped to spanning tree 2.

<device> system-view

[device] stp region-configuration [device-mst-region] region-name info

[device-mst-region] instance 1 vlan 2 to 10

[device-mst-region] instance 2 vlan 20 to 30

[device-mst-region] revision-level 1

[device-mst-region] active region-configuration

# Verify the above configuration.

[device-mst-region] check region-configuration Admin configuration

Format selector

:0

Region name

:info

Revision level

:1

Instance Vlans Mapped

011 to 19, 31 to 4094

11 to 10

220 to 30

Specifying the Current Device as a Root Bridge/Secondary Root Bridge

MSTP can automatically choose a device as a root bridge through calculation. You can also manually specify the current device as a root bridge by using the corresponding commands.

Specify the current device as the root bridge of a spanning tree

Follow these steps to specify the current device as the root bridge of a spanning tree:

1-17

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3Com WX3000 operation manual Configuration example, # Verify the above configuration