Cisco WS-C2950SX-48-SI Configuration Manual page 147

Chapter 7 Configuring Spanning Tree
Console> (enable) show spantree mst 3
Spanning tree mode
Instance
VLANs Mapped:
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
Bridge ID MAC ADDR
Bridge ID Priority
Port
------------------------ ------------- ---- -------- ----
--------------------
6/1
Boundary(PVST)
6/2
Boundary(PVST)
Configuring the MST Port Cost
You can configure the port cost of switch ports.The switch uses ports with lower port costs to forward
frames. Assign lower numbers to ports attached to faster media (such as full duplex) and higher numbers
to ports attached to slower media. The possible range is from 1–65,535. The default differs for different
media. The path cost is typically 1000 ÷ LAN speed in megabits per second.
To configure the port cost for a port, perform this task in privileged mode:
Task
Step 1
Configure the MST port cost for a switch port.
Step 2 Verify the port cost setting.
This example shows how to configure the port cost on an MST instance and verify the configuration:
Console> (enable) set spantree portcost 6/1 10000 mst
Spantree port 6/1 path cost set to 10000.
Console> (enable)
Console> (enable) show spantree mst 6/1
Edge Port:
Link Type:
Port Guard:
Boundary:
Inst State
---- ------------- ---- --------- ----
-----------------------------------
0 forwarding
1 forwarding
2 forwarding
3 forwarding
4 forwarding
Console> (enable)
78-15486-01
MST
3
31-40
00-10-7b-bb-2f-00
8195
0
1/0
00-10-7b-bb-2f-00
8195
State
forwarding
blocking
No, (Configured) Default
P2P, (Configured) Auto
Default
Yes (PVST)
Role Cost
ROOT 10000
BDRY 10000
BDRY 10000
BDRY 10000
BDRY 10000
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
(root priority:8192, sys ID ext:3)
Remaining Hops 20
(bridge priority:8192, sys ID ext:3)
Role Cost Prio Type
BDRY 20000 32 P2P,
BDRY 20000 32 P2P,
Command
set spantree portcost mod/port cost [mst]
show spantree mst [instance | mod/port]
Prio VLANs
32 1
32 2-20
32 21-30
32 31-40
32 41-50
Configuring MST
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Release 8.1
7-51