3Com Switch 8800 Family Configuration Guide

Configuring MSTP 133
display commands. For detailed information, refer to the "Display and Debug
MSTP" section.
n
When GVRP and MSTP start on the switch simultaneously, GVRP packets will
propagate along CIST which is a spanning tree instance. In this case, if you want to
issue a certain VLAN through GVRP on the network, you should make sure that
the VLAN is mapped to CIST when configuring the VLAN mapping table of MSTP.
CIST is spanning tree instance 0.
Configuring the MST
Region for a Switch
Which MST region a switch belongs to is determined with the configurations of
the region name, VLAN mapping table, and MSTP revision level. You can perform
the following configurations to put a switch into an MST region.
Entering MST region view
Perform the following configuration in system view.
Configuring parameters for the MST region
Perform the following configuration in MST region view.
An MST region can contain up to 49 spanning tree instances, among which the
Instance 0 is IST and the Instances 1 through 48 are MSTIs. Upon the completion
of the above configurations, the current switch is put into a specified MST region.
Note that 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 same 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 bate such flapping, MSTP triggers to recalculate the spanning tree
according to the configurations only if one of the following conditions is met:
■ A user manually activates the configured parameters related to the MST region,
using the active region-configuration command.
■ A user enables MSTP using the stp enable command.
Tab le 104 Enter MST region view
Operation Command
Enter MST region view (from system view) stp region-configuration
Restore the default settings of MST region undo stp region-configuration
Tab le 105 Configure the MST region for a switch
Operation Command
Configure the 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 instance-id [ vlan vlan-list ]
Configure the MSTP revision level of MST
region
revision-level level
Restore the MSTP revision level of MST region undo revision-level