Cisco WS-C2950SX-48-SI Configuration Manual page 149

Chapter 7 Configuring Spanning Tree
Console> (enable) show spantree mst 4
Spanning tree mode
Instance
VLANs Mapped:
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
Bridge ID MAC ADDR
Bridge ID Priority
4)
Port
------------------------ ------------- ---- -------- -----------------
6/1
Boundary(PVST)
6/2
Boundary(PVST)
Console> (enable)
Configuring the MST Port Instance Priority
You can set a port priority for an instance of MST. The port with the lowest priority for a specific MST
instance forwards frames for that instance. The port instance range is from 0–63. If all ports have the
same priority for an MST instance, the port with the lowest port number forwards frames for that
instance.
To configure the port instance priority on an MST instance, perform this task in privileged mode:
Task
Step 1 Configure the port instance priority on an MST
instance.
Step 2
Verify the port instance priority setting.
This example shows how to configure the port instance priority on an MST instance and verify the
configuration:
Console> (enable) set spantree portinstancepri 6/1 20 mst 2
Port 6/1 MST Instances 2 using portpri 20.
Port 6/1 MST Instances 0-1,3-15 using portpri 30.
Console> (enable)
Console> (enable)
Console> (enable) show spantree mst 2
Spanning tree mode
Instance
VLANs Mapped:
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
78-15486-01
MST
4
41-50
00-10-7b-bb-2f-00
32772
0
1/0
00-10-7b-bb-2f-00
32772
State
forwarding
blocking
MST
2
21-30
00-10-7b-bb-2f-00
32770
0
1/0
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
(root priority:32768, sys ID ext:4)
Remaining Hops 20
(bridge priority:32768, sys ID ext:
Role Cost Prio Type
BDRY 5000 30 P2P,
BDRY 20000 32 P2P,
Command
set spantree portinstancepri mod/port
priority mst [instance]
show spantree mst [instance | mod/port]
(root priority:32768, sys ID ext:2)
Remaining Hops 20
Configuring MST
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Release 8.1
7-53