Users Guide

Layer 2 Switching Commands 791
Syntax
instance instance-id {add | remove} vlan vlan-list
• instance-ID — ID of the MST instance. (Range: 1-4094)
• vlan-list — VLANs to be added to the existing MST instance. To specify a
range of VLANs, use a hyphen. To specify a series of VLANs, use a comma.
(Range: 1-4094)
Default Configuration
VLANs are mapped to the common and internal spanning tree (CIST)
instance (instance 0).
Command Mode
MST mode
User Guidelines
Before mapping VLANs to an instance use the spanning-tree mst enable
command to enable the instance.
All VLANs that are not explicitly mapped to an MST instance are mapped to
the common and internal spanning tree (CIST) instance (instance 0) and
cannot be unmapped from the CIST.
For two or more switches to be in the same MST region, they must have the
same VLAN mapping, the same configuration revision number, and the same
configuration name.
Dell EMC Networking MSTP supports mapping of VLANs to MST instances,
even though the underlying VLAN may not be defined on the switch. Traffic
received on VLANs not defined on the port received is dropped.
For interoperability purposes, VLAN 4094 may be mapped to an MSTI,
however, VLAN 4094 is reserved internally and may not be used to forward
traffic.
Example
The following example maps the entire range of VLANs to MST instances
(MST instance 0 is mapped to VLAN 1 by default). Additionally, two 10G
ports have some, but not all, of the VLANs mapped to MST instances.