MST instances

You can create up to 15 mst-instances. They can range from 1 to 4094. By changing path-cost and priorities, you can ensure that each instance forms its own tree within the region, therefore ensure that different VLANs follow different paths.

You can assign non-overlapping VLAN ranges to each instance. VLANs that are not assigned to an instance are implicitly assumed to be in instance 0, which is also called the CIST. This CIST cannot be deleted or created.

The parameters that can be defined per instance are mst-priority and vlan-range.

mst-priority

the bridge-priority for this specific mst-instance. It follows the same rules as bridge-priority. For the CIST, the bridge-priority is used.

vlan-range

the VLANs are mapped to this specific mst-instance. If no VLAN-ranges are defined in any mst-instances, then all VLANs are mapped to the CIST.