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Spanning Tree Commands
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mst vlan
This command adds VLANs to a spanning tree instance. Use the no form to remove
the specified VLANs. Using the no form without any VLAN parameters to remove all
VLANs.
Syntax
[no] mst instance_id vlan vlan-range
• instance_id - Instance identifier of the spanning tree. (Range: 0-4094)
• vlan-range - Range of VLANs. (Range: 1-4093)
Default Setting
none
Command Mode
MST Configuration
Command Usage
• Use this command to group VLANs into spanning tree instances. MSTP
generates a unique spanning tree for each instance. This provides multiple
pathways across the network, thereby balancing the traffic load, preventing
wide-scale disruption when a bridge node in a single instance fails, and
allowing for faster convergence of a new topology for the failed instance.
• By default all VLANs are assigned to the Internal Spanning Tree (MSTI 0) that
connects all bridges and LANs within the MST region. This switch supports up
to 33 instances. You should try to group VLANs which cover the same general
area of your network. However, remember that you must configure all bridges
within the same MSTI Region (page 4-168) with the same set of instances,
and the same instance (on each bridge) with the same set of VLANs. Also,
note that RSTP treats each MSTI region as a single node, connecting all
regions to the Common Spanning Tree.
Example
Console(config-mstp)#mst 1 vlan 2-5
Console(config-mstp)#