To create or modify an MST Instance:
In the left navigation pane, go to Node Interfaces > Bridge > MSTP > MST Instances.
You may create a maximum of 31 MST Instances,
Click the Create MST Instance ( ) icon at the top of the MST Instances page.
A descriptive name for the instance.
A unique integer identifier for this instance.
MSTP instance's priority in increments of 4096. The lower the priority, the higher the chances of this SBC becoming the root bridge.