20-29
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 20 Configuring STP and Prestandard IEEE 802.1s MST
Configuring STP
To configure the STP port cost of a Layer 2 LAN interface, perform this task:
This example shows how to change the STP port cost of Fast Ethernet port 4/4:
Router#
configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
interface fastEthernet 4/4
Router(config-if)#
spanning-tree cost 1000
Router(config-if)#
^Z
Router#
This example shows how to verify the configuration:
Router#
show spanning-tree interface fastEthernet 4/4
Vlan Role Sts Cost Prio.Nbr Status
---------------- ---- --- --------- -------- --------------------------------
VLAN0001 Back BLK 1000 160.196 P2p
VLAN0006 Back BLK 1000 160.196 P2p
VLAN0007 Back BLK 1000 160.196 P2p
VLAN0008 Back BLK 1000 160.196 P2p
VLAN0009 Back BLK 1000 160.196 P2p
VLAN0010 Back BLK 1000 160.196 P2p
Router#
This example shows how to configure the port priority at an individual port VLAN cost for VLAN 200:
Router#
configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
interface fastEthernet 4/4
Router(config-if)#
spanning-tree vlan 200 cost 2000
Router(config-if)#
^Z
Router#
This example shows how to verify the configuration:
Router#
show spanning-tree vlan 200 interface fastEthernet 4/4
Interface Role Sts Cost Prio.Nbr Status
---------------- ---- --- --------- -------- --------------------------------
Command
Purpose
Step 1
Router(config)#
interface
{{
type
1
slot/port
} |
{
port-channel
port_channel_number
}}
1.
type
=
ethernet
,
fastethernet
,
gigabitethernet
, or
tengigabitethernet
Selects an interface to configure.
Step 2
Router(config-if)#
spanning-tree cost
port_cost
Configures the port cost for the LAN interface. The
port_cost
value can be from 1 to 200000000 (1 to 65535
in Release 12.1(2)E and earlier releases).
Router(config-if)#
no
spanning-tree cost
Reverts to the default port cost.
Step 3
Router(config-if)# [
no
]
spanning-tree vlan
vlan_ID
cost
port_cost
Configures the VLAN port cost for the LAN interface.
The
port_cost
value can be from 1 to 200000000. The
vlan_ID
value can be 1 through 4094, except reserved
VLANs (see
Table 14-1 on page 14-2
).
Step 4
Router(config-if)#
no
spanning-tree vlan
vlan_ID
cost
Reverts to the default VLAN port cost.
Step 5
Router(config-if)#
end
Exits configuration mode.
Step 6
Router#
show spanning-tree
interface
{
type
1
slot/port
} | {
port-channel
port_channel_number
}
show spanning-tree vlan
vlan_ID
Verifies the configuration.