Cisco 7604 Configuration Manual page 297

Chapter 20 Configuring STP and Prestandard IEEE 802.1s MST
Command
Step 2
Router(config)# end
Step 3
Router# show spanning-tree vlan vlan_ID
Caution Do not disable spanning tree on a VLAN unless all switches and bridges in the VLAN have spanning
tree disabled. You cannot disable spanning tree on some switches and bridges in a VLAN and leave it
enabled on other switches and bridges in the VLAN. This action can have unexpected results because
switches and bridges with spanning tree enabled will have incomplete information regarding the physical
topology of the network.
Caution We do not recommend disabling spanning tree, even in a topology that is free of physical loops. Spanning
tree serves as a safeguard against misconfigurations and cabling errors. Do not disable spanning tree in
a VLAN without ensuring that there are no physical loops present in the VLAN.
This example shows how to enable STP on VLAN 200:
Router# configure terminal
Router(config)# spanning-tree vlan 200
Router(config)# end
Router#
Because STP is enabled by default, entering a show running command to view the resulting
Note
configuration does not display the command you entered to enable STP.
This example shows how to verify the configuration:
Router# show spanning-tree vlan 200
VLAN0200
Spanning tree enabled protocol ieee
Root ID
Bridge ID
Interface
---------------- ---- --- --------- -------- --------------------------------
Fa4/4
Fa4/5
Router#
Note You must have at least one interface that is active in VLAN 200 to create a VLAN 200 spanning tree. In
this example, two interfaces are active in VLAN 200.
OL-4266-08
Priority 32768
Address 00d0.00b8.14c8
This bridge is the root
Hello Time 2 sec Max Age 20 sec
Priority 32768
Address 00d0.00b8.14c8
Hello Time 2 sec Max Age 20 sec
Aging Time 300
Role Sts Cost
Desg FWD 200000
Back BLK 200000
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
Purpose
Exits configuration mode.
Verifies that STP is enabled.
Forward Delay 15 sec
Forward Delay 15 sec
Prio.Nbr Status
128.196 P2p
128.197 P2p
Configuring STP
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