3Com 10014298 Configuring the MST Region, Perform the following configuration in MST region view

Configuring MSTP 191

Configuring the MST Region

Perform the following configuration in MST region view.

Table 190 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-idvlan
	vlan-list
Restore the default VLAN mapping table	undo instance
Configure the MSTP revision level of MST	revision-level level
region
Restore the MSTP revision level of MST region	undo revision-level

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-configurationcommand.

■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-configurationcommand in system view.

Activating the MST Region Configuration and Exiting the MST Region View

Perform the following configuration in MST region view.

Table 191 Activate the MST Region Configuration and Exit the MST Region View

Operation	Command
Show the configuration information of the	check region-configuration
MST region under revision (from MST region
view)
Manually activate the MST region	active region-configuration
configuration (from MST region view)
Exit MST region view (from MST region view)	quit

Specifying the Switch as MSTP can determine the spanning tree root through calculation. You can also Primary or Secondary specify the current switch as the root, using the command provided by the switch.

Root Switch