Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 543)

Spanning Tree Commands
Software Reference for x310 Series Switches
C613-50046-01 REV A AlliedWare Plus TM Operating System - Version 5.4.4C 19.53
spanning-tree mst instance priority
Use this command in Interface Configuration mode for a switch port interface only to set
the port priority for an MST instance (MSTI).
Use the no variant of this command to restore the default priority value (128).
Syntax spanning-tree mst instance priority <priority>
no spanning-tree mst instance [priority]
Default The default is 128.
Mode Interface Configuration mode for a switch port interface.
Usage This command sets the value of the priority field contained in the port identifier. The MST
algorithm uses the port priority when determining the root port for the switch in the MSTI.
The port with the lowest value is considered to have the highest priority and will be
chosen as root port over a port - equivalent in all other aspects - but with a higher priority
value.
Examples
Related Commands instance vlan (MSTP)
spanning-tree priority (port priority)
spanning-tree mst instance
spanning-tree mst instance path-cost
spanning-tree mst instance restricted-role
spanning-tree mst instance restricted-tcn
Parameter Description
Specify the MSTI identifier in the range <1-15>.
<priority> This must be a multiple of 16 and within the range <0-240>.
A lower priority indicates greater likelihood of the port becoming
the root port.
awplus# configure terminal
awplus(config)# interface port1.0.2
awplus(config-if)# spanning-tree mst instance 3 priority 112
awplus# configure terminal
awplus(config)# interface port1.0.2
awplus(config-if)# no spanning-tree mst instance 3 priority