Cisco Systems N3KC3048TP1GE Mapping and Unmapping VLANs to MST Instances, Procedure, Purpose

Configuring Multiple Spanning Tree

Mapping and Unmapping VLANs to MST Instances

Mapping and Unmapping VLANs to MST Instances

Caution When you change the VLAN-to-MSTI mapping, the system restarts MST.

Note You cannot disable an MSTI.

For two or more bridges to be in the same MST region, they must have the identical MST name,

VLAN-to-instance mapping, and MST revision number.

Procedure

	Command or Action	Purpose
Step 1	switch# configure terminal	Enters configuration mode.
Step 2	switch(config)# spanning-tree mst	Enters MST configuration submode.
	configuration
Step 3	switch(config-mst)# instance	Maps VLANs to an MST instance, as follows:
	instance-id vlan vlan-range

• For instance-idthe range is from 1 to 4094.

		Instance 0 is reserved for the IST for each MST
		region.
		• For vlan-rangethe range is from 1 to 4094.
		When you map VLANs to an MSTI, the mapping is
		incremental, and the VLANs specified in the
		command are added to or removed from the VLANs
		that were previously mapped.
Step 4	switch(config-mst)# no instance	Deletes the specified instance and returns the VLANs to
	instance-id vlan vlan-range	the default MSTI, which is the CIST.

This example shows how to map VLAN 200 to MSTI 3:

switch# configure terminal

switch(config)# spanning-tree mst configuration switch(config-mst)# instance 3 vlan 200

Mapping Secondary VLANs to Same MSTI as Primary VLANs for Private VLANs

When you are working with private VLANs on the system, all secondary VLANs must be in the same MSTI and their associated primary VLAN.

	Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
102	OL-26590-01