3Com 3.01.01 Switch User Manual


 
Configuring MSTP 251
Configuring the MST Region
Perform the following configuration in MST region view.
An MST region can contain up to 16 spanning tree instances, among which
Instance 0 is an IST and instances 1 through 16 are MSTIs. Upon the completion of
these configurations, the current switch is put into a specified MST region.
Two switches belong to the same MST region only if they have been configured
with the same MST region name, STI-VLAN mapping tables of an MST region, and
the MST region revision level.
Configuring the related parameters, especially the VLAN mapping table, of the
MST region will lead to the recalculation of spanning tree and network topology
flapping. To reduce such flapping, MSTP triggers to recalculate the spanning tree
according to the configurations only if one of the following conditions are met:
The user manually activates the configured parameters related to the MST
region, using the active region-configuration command.
The user enables MSTP, using the stp enable command.
By default, the MST region name is the first switch MAC address, all the VLANs in
the MST region are mapped to the STI 0, and the MSTP region revision level is 0.
You can restore the default settings of MST region, using the undo stp
region-configuration command in system view.
Activating the MST Region Configuration and Exiting the MST Region
View
Perform the following configuration in MST region view.
Specifying the Switch as
Primary or Secondary
Root Switch
MSTP can determine the spanning tree root through calculation. You can also
specify the current switch as the root, using the command provided by the switch.
Table 2 Configure the MST Region for a Switch
Operation Command
Configure MST region name region-name name
Restore the default MST region name undo region-name
Configure VLAN mapping table instance instance-id vlan vlan-list
Restore the default VLAN mapping table undo instance
Configure the MSTP revision level of MST
region
revision-level level
Restore the MSTP revision level of MST region undo revision-level
Table 3 Activate the MST Region Configuration and Exit the MST Region View
Operation Command
Show the configuration information of the
MST region under revision (from MST region
view)
check region-configuration
Manually activate the MST region
configuration (from MST region view)
active region-configuration
Exit MST region view (from MST region view) quit