3com WX3000 Manuel D’Utilisation

 

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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

 

Activate the new MST region-related settings by using the active region-configuration command 

z

 

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. 

 

# 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 

      0       11 to 19, 31 to 4094 

      1       1 to 10 

      2       20 to 30 

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. 

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