C613-50170-01 Rev B
Command Reference for x510 Series
680
AlliedWare Plus™ Operating System - Version 5.4.7-1.x
S
PANNING
T
REE
C
OMMANDS
SPANNING
-
TREE
MST
INSTANCE
PATH
-
COST
spanning-tree mst instance path-cost
Overview
Use this command to set the cost of a path associated with a switch port, for the
specified MSTI.
This specifies the switch port’s contribution to the cost of a path to the MSTI
regional root via that port. This applies when the port is the root port for the MSTI.
Use the
no
variant of this command to restore the default cost value of the path.
Syntax
spanning-tree mst instance
<instance-id>
path
-
cost
<path-cost>
no spanning-tree mst instance
<instance-id>
path-cost
Default
The default path cost values and the range of recommended path cost values
depend on the port speed, as shown in the following table from the IEEE
802.1q-2003 standard.
Mode
Interface Configuration mode for a switch port interface only.
Usage
Before you can use this command to set a path-cost in a VLAN configuration, you
must explicitly add an MST instance to a port using the
command.
Examples
To set a path cost of 1000 on instance 3, use the commands:
awplus#
configure terminal
awplus(config)#
interface port1.0.2
awplus(config-if)#
spanning-tree mst instance 3 path-cost 1000
Parameter
Description
<
instance-id
>
Specify an MSTP instance in the range 1-15.
<path-cost>
Specify the cost of path in the range of <
1-200000000
>, where
a lower path-cost indicates a greater likelihood of the specific
interface becoming a root.
Port speed
Default path cost
Recommended path cost range
Less than 100 Kb/s
1Mbps
10Mbps
100 Mbps
1 Gbps
10 Gbps
100 Gbps
1Tbps
10 Tbps
200,000,000
20,000,000
2,000,000
200,000
20,000
2,000
200
20
2
20,000,000-200,000,000
2,000,000-20,000,000
200,000-2,000,000
20,000-200,000
2,000-20,000
200-2,000
20-200
2-200
2-20