Configuring Spanning Tree - Cisco NM-8B-U - HW ROUTERS L-M User Manual

16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series

Configuring Spanning Tree

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Enabling Spanning Tree
You can enable spanning tree on a per-VLAN basis. The switch maintains a separate instance of
spanning tree for each VLAN (except on VLANs on which you disable spanning tree).
To enable spanning tree on a per-VLAN basis, use the following commands in global configuration
mode:
Command
Step 1
Router(config)# spanning-tree vlan vlan-id
Step 2
Router(config)# end
Verify Spanning Tree
Use the show spanning-tree vlan command to verify spanning tree configuration:
Step 1
Router# show spanning-tree vlan 200
VLAN200 is executing the ieee compatible Spanning Tree protocol
Bridge Identifier has priority 32768, address 0050.3e8d.6401
Configured hello time 2, max age 20, forward delay 15
Current root has priority 16384, address 0060.704c.7000
Root port is 264 (FastEthernet5/8), cost of root path is 38
Topology change flag not set, detected flag not set
Number of topology changes 0 last change occurred 01:53:48 ago
Times:
Timers: hello 0, topology change 0, notification 0
Port 264 (FastEthernet5/8) of VLAN200 is forwarding
Port path cost 19, Port priority 128, Port Identifier 129.9.
Designated root has priority 16384, address 0060.704c.7000
Designated bridge has priority 32768, address 00e0.4fac.b000
Designated port id is 128.2, designated path cost 19
Timers: message age 3, forward delay 0, hold 0
Number of transitions to forwarding state: 1
BPDU: sent 3, received 3417
Enabling Spanning Tree, page 67
Configuring Spanning Tree Port Priority, page 68
Configuring Spanning Tree Port Cost, page 68
Configuring the Bridge Priority of a VLAN, page 69
Configuring the Hello Time, page 70
Configuring the Forward-Delay Time for a VLAN, page 70
Configuring the Maximum Aging Time for a VLAN, page 70
Configuring BackboneFast, page 71
Disabling Spanning Tree, page 72
hold 1, topology change 24, notification 2
hello 2, max age 14, forward delay 10
Purpose
Enables spanning tree on a per-VLAN basis.
Exits configuration mode.
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
Configuration Tasks
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