3Com 4500 Configuration Manual page 195

To do...
Configure the name of the MST
region
Configure the VLAN-to-instance
mapping table for the MST region
Configure the MSTP revision
level for the MST region
Activate the configuration of the
MST region manually
Display the configuration of the
current MST region
Display the currently valid
configuration of the MST region
Neighbor Topology Discovery Protocol (NTDP) packets sent by devices in a cluster can only be
transmitted within the MSTI where the management VLAN of the cluster resides. For more information
about clusters and the NTDP protocol, see Cluster Operation.
Configuring MST region-related parameters (especially the VLAN-to-instance 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:
Activate the new MST region-related settings by using the active region-configuration command
Enable MSTP by using the stp enable command
MSTP-enabled switches are in the same region only when they have the same format selector (a
802.1s-defined protocol selector, which is 0 by default and cannot be configured), MST region
name, VLAN-to-instance mapping table, and revision level.
The 3Com switches 4500 support only the MST region name, VLAN-to-instance mapping table,
and revision level. Switches with the settings of these parameters being the same are assigned to
the same MST region.
Use the command...
region-name name
instance instance-id vlan
vlan-list
vlan-mapping modulo
modulo
revision-level level
active
region-configuration
check
region-configuration
display stp
region-configuration
1-17
Remarks
Required
The default MST region name of a
switch is its MAC address.
Required
Both commands can be used to
configure VLAN-to-instance
mapping tables.
By default, all VLANs in an MST
region are mapped to MSTI 0.
Required
The default revision level of an
MST region is level 0.
Required
Optional
Available in any view