3Com Switch 7750 Series
Command Reference Guide – MSTP Chapter 1 MSTP Configuration Commands
1-6
Field Description
Revision level The revision level of the MST region
Instance Vlans Mapped Spanning tree instance-to-VLAN mappings in the
MST region
Syntax
instance instance-id vlan vlan-list
undo instance instance-id [ vlan vlan-list ]
View
MST region view
Parameter
instance-id: ID of a spanning tree instance ranging from 0 to 16. A value of 0 specifies
the CIST.
vlan-list: List of VLANs. You need to provide this argument in the form of vlan-list =
{ vlan-id [ to vlan-id ] }&<1-10>, where &<1-10> means that you can provide up to 10
VLAN IDs/VLAN ID ranges for this argument. Normally, a VLAN ID can be a number
ranging from 1 to 4094. VLANs with their IDs beyond this range (if the switch supports
this kind VLAN IDs), such as VLAN 4095, VLAN 4096, can only be mapped to the CIST
(spanning tree instance 0).
Description
Use the instance command to map specified VLANs to a specified spanning tree
instance.
Use the undo instance command to remove the mappings from the specified VLANs
to the specified spanning tree instance and remap the specified VLANs to the CIST
(spanning tree instance 0). If you specify no VLAN in the undo instance command, all
VLANs that are mapped to the specified spanning tree instance are remapped to the
CIST.
By default, all VLANs are mapped to the CIST.
VLAN-to-spanning tree instance mappings are recorded in the VLAN mapping table of
an MSTP switch. So these two commands are actually used to manipulate the VLAN
mapping table. You can add/remove a VLAN to/from the VLAN mapping table of a
specific spanning tree instance by using these two commands.