Spanning Tree Commands
©2008 Allied Telesis Inc. All rights reserved.
Software Version 5.2.1
AlliedWare Plus
TM
Operating System Software Reference C613-50003-00 REV E
19.7
instance priority (MSTP)
Use this command to set the priority for this device to become the root bridge for the
specified MSTI.
Use this command for MSTP only.
Use the
no
version of this command to restore the root bridge priority of the device for the
instance to the default.
Syntax
instance <
msti-id
> priority <
priority
>
no instance <
msti-id
> priority <
priority
>
Default
The default priority value for all instances is 32768.
Mode
MST Configuration Mode
Usage
MSTP lets you distribute traffic more efficiently across a network by blocking different links for
different VLANs. You do this by making different devices into the root bridge for each MSTP
instance, so that each instance blocks a different link.
If all devices have the same root bridge priority for the instance, MSTP selects the device with
the lowest MAC address to be the root bridge. Give the device a higher priority for becoming
the root bridge for a particular instance by assigning it a lower priority number, or vice versa.
Example
To set the root bridge priority for MSTP instance 2 to be the highest (0), so that it will be the
root bridge for this instance when available, use the commands:
To reset the root bridge priority for instance 2 to the default (32768), use the commands:
Related Commands
region (MSTP)
revision (MSTP)
show spanning-tree mst config
spanning-tree mst instance
spanning-tree mst instance priority
Parameter
Description
<msti-id>
The MST instance ID (1-15).
<priority>
<0-61440> Specify the root bridge priority for the device for the MSTI. A
lower priority number indicates a greater likelihood of the device
becoming the root bridge. The priority values can be set only in
increments of 4096. If you specify a number hat is not a multiple of 4096, it
will be rounded down.
Default: 32768
awplus#
configure terminal
awplus(config)#
spanning-tree mst configuration
awplus(config-mst)#
instance 2 priority 0
awplus#
configure terminal
awplus(config)#
spanning-tree mst configuration
awplus(config-mst)#
no instance 2 priority