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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 7 Configuring Spanning Tree
Configuring Multiple Spanning Tree on the Switch
---------- ---------------------------------------------------------
5000 4
Default 200000 0-3,5-4094
Console> (enable)
set spantree portinstancecost 4/1 cost 6000 mst 4000
Command successful. Modified port 4/1 configuration:
Cost Instances
---------- ---------------------------------------------------------
5000 4
6000 4000
Default 200000 0-3,5-3999,4001-4094
Console> (enable)
show spantree portinstancecost 4/1
This command is not valid when STP is in MST mode.
Console> (enable)
show spantree portinstancecost 4/1 mst
Port 4/1 cost configuration:
Cost Instances
---------- ---------------------------------------------------------
5000 4
6000 4000
Default 200000 0-3,5-3999,4001-4094
Console> (enable)
Configuring the MST Port Instance Priority
You can set the port priority for an instance of MST. The port with the lowest priority value for a specific
MST instance forwards the frames for that instance. The possible port instance range is 0–240. If all
ports have the same priority value for an MST instance, the port with the lowest port priority number
forwards the frames for that instance.
You can assign a different port instance priority for instances within a trunk port.
To configure the port instance priority on an MST instance, perform this task in privileged mode:
This example shows how to configure the port instance priority on an MST instance and verify the
configuration:
Console> (enable)
set spantree portinstancepri 4/1 16 mst 2
Command successful. Modified port 4/1 configuration:
Priority Instances
---------- ---------------------------------------------------------
16 2
Default 32 0-1,3-4094
Console> (enable)
set spantree portinstancepri 4/1 48 mst 200
Command successful. Modified port 4/1 configuration:
Priority Instances
---------- ---------------------------------------------------------
16 2
48 200
Default 32 0-1,3-199,201-4094
Console> (enable)
show spantree mst 4/1
Edge Port: No, (Configured) Default
Link Type: P2P, (Configured) Auto
Port Guard: Default
Boundary: No
Task
Command
Step 1
Configure the port instance priority on an MST
instance.
set spantree portinstancepri
mod/port
priority
mst
[
instance
]
Step 2
Verify the port instance priority setting.
show spantree mst
[
instance
|
mod/port
]