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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 18 Configuring STP and MST
Configuring STP
This example shows how to change the spanning tree port cost of a Fast Ethernet interface:
Switch# configure terminal
Switch(config)# interface fastethernet 5/8
Switch(config-if)# spanning-tree cost 18
Switch(config-if)# end
Switch#
This example shows how to verify the configuration of the interface when it is configured as an access
port:
Switch# show spanning-tree interface fastethernet 5/8
Port 264 (FastEthernet5/8) of VLAN200 is forwarding
Port path cost 18, Port priority 100, Port Identifier 129.8.
Designated root has priority 32768, address 0010.0d40.34c7
Designated bridge has priority 32768, address 0010.0d40.34c7
Designated port id is 128.1, designated path cost 0
Timers: message age 2, forward delay 0, hold 0
Number of transitions to forwarding state: 1
BPDU: sent 0, received 13513
Switch#
This example shows how to configure the spanning tree VLAN port cost of a Fast Ethernet interface:
Switch# configure terminal
Switch(config)# interface fastethernet 5/8
Switch(config-if)# spanning-tree vlan 200 cost 17
Switch(config-if)# end
Switch#
This example shows how to verify the configuration of VLAN 200 on the interface when it is configured
as a trunk port:
Switch# show spanning-tree vlan 200
<...output truncated...>
Port 264 (FastEthernet5/8) of VLAN200 is forwarding
Port path cost 17, Port priority 64, Port Identifier 129.8.
Designated root has priority 32768, address 0010.0d40.34c7
Designated bridge has priority 32768, address 0010.0d40.34c7
Designated port id is 128.1, designated path cost 0
Timers: message age 2, forward delay 0, hold 0
Command Purpose
Step 1 Switch(config)# interface {{fastethernet |
gigabitethernet | tengigabitethernet} slot/port}
| {port-channel port_channel_number}
Specifies an interface to configure.
Step 2 Switch(config-if)# [no] spanning-tree cost
port_cost Configures the port cost for an interface. The port_cost
value can be from 1 to 200,000,000.
Use the no keyword to restore the defaults.
Step 3 Switch(config-if)# [no] spanning-tree vlan
vlan_ID cost port_cost Configures the VLAN port cost for an interface. The
port_cost value can be from 1 to 200,000,000.
Use the no keyword to restore the defaults.
Step 4 Switch(config-if)# end Exits configuration mode.
Step 5 Switch# show spanning-tree interface
{{fastethernet | gigabitethernet} slot/port} |
{port-channel port_channel_number}
show spanning-tree vlan vlan_ID
Verifies the configuration.