20-30
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
Fa4/4 Desg FWD 2000 64.196 P2p
Note
In the following output other VLANs (VLAN 1 for example) have not been affected by this
configuration.
Router#
show spanning-tree vlan 1 interface fastEthernet 4/4
Interface Role Sts Cost Prio.Nbr Status
---------------- ---- --- --------- -------- --------------------------------
Fa4/4 Back BLK 1000 160.196 P2p
Router#
Note
The
show spanning-tree
command only displays information for ports that are in link-up operative state
and are appropriately configured for DTP. If these conditions are not met, you can enter a
show
running-config
command to confirm the configuration.
Configuring the Bridge Priority of a VLAN
Note
Be careful when using this command. For most situations, we recommend that you enter the
spanning-tree vlan
vlan_ID
root primary
and the
spanning-tree vlan
vlan_ID
root secondary
commands to modify the bridge priority.
To configure the STP bridge priority of a VLAN when the extended system ID is disabled, perform this
task:
To configure the STP bridge priority of a VLAN when the extended system ID is enabled, perform this
task:
Command
Purpose
Step 1
Router(config)#
spanning-tree vlan
vlan_ID
priority
bridge_priority
Configures the bridge priority of a VLAN when the
extended system ID is disabled. The
bridge_priority
value can be from 1 to 65535. The
vlan_ID
value can be
1 through 4094, except reserved VLANs (see
Table 14-1
on page 14-2
).
Router(config)#
no
spanning-tree vlan
vlan_ID
priority
Reverts to the default bridge priority value.
Step 2
Router(config)#
end
Exits configuration mode.
Step 3
Router#
show spanning-tree
vlan
vlan_ID
bridge
[
detail
]
Verifies the configuration.
Command
Purpose
Step 1
Router(config)# [
no
]
spanning-tree vlan
vlan_ID
priority
{
0
|
4096
|
8192
|
12288
|
16384
|
20480
|
24576
|
28672
|
32768
|
36864
|
40960
|
45056
|
49152
|
53248
|
57344
|
61440
}
Configures the bridge priority of a VLAN when the
extended system ID is enabled. The
vlan_ID
value can be
1 through 4094, except reserved VLANs (see
Table 14-1
on page 14-2
).
Router(config)#
no
spanning-tree vlan
vlan_ID
priority
Reverts to the default bridge priority value.
