Multiple Spanning Tree Configuration

Multiple Spanning Tree can be configured on a Cisco Switch with these instructions:

1. In global configuration mode, enter the command spanning-tree mode mst to change the spanning tree mode on the switch to Multiple Spanning Tree.
2. Define the Multiple Spanning Tree Instance priority by following one of the two methods below in global configuration mode (X is the instance number and Y is the priority value):
   1. spanning-tree mst X priority Y
   2. spanning-tree mst X root primary
3. Associate VLANs to the Multiple Spanning Tree instance. By default all VLANs are associated with the special instance number of 0. This can be changed by entering the Multiple Spanning Tree sub configuration mode with the command spanning-tree mst configuration and assigning VLANs to instances with the command instance X vlan Y. X is the instance number and Y is the VLAN number.
4. Staying within the MST sub-mode configuration, the version number needs to be specified. This must match across all switches in the same MST region. It can be specified with revision X where X is the revision number.
5. Give the MST region a name, this can be set with name X in the MST submode configuration. X is the string of the name chosen.

Outside of MST sub-mode, the configuration can be checked with the command show spanning-tree mst configuration