Enabling Loop Guard - Cisco 7604 Configuration Manual

Chapter 21 Configuring Optional STP Features
Command
Step 1
Router(config)# interface { type
{port-channel port_channel_number }
Step 2
Router(config-if)# spanning-tree guard root
Router(config-if)# no spanning-tree guard root
Step 3
Router(config-if)# end
Step 4
Router# show spanning-tree
Router# show running interface { type
{port-channel port_channel_number }
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
To display ports that are in the root-inconsistent state, enter the show spanning-tree inconsistentports
command.

Enabling Loop Guard

To enable loop guard globally on the router, perform this task:
Command
Step 1
Router(config)# spanning-tree loopguard default
Step 2
Router(config)# end
Step 3
Router# show spanning-tree interface 4/4 detail
This example shows how to enable loop guard globally:
Router# configure terminal
Enter configuration commands, one per line.
Router(config)# spanning-tree loopguard default
Router(config)# ^Z
Router# show spanning-tree interface fastEthernet 4/4 detail
Port 196 (FastEthernet4/4) of VLAN0010 is forwarding
Port path cost 1000, Port priority 160, Port Identifier 160.196.
Designated root has priority 32768, address 00d0.00b8.140a
Designated bridge has priority 32768, address 00d0.00b8.140a
Designated port id is 160.196, designated path cost 0
Timers:message age 0, forward delay 0, hold 0
Number of transitions to forwarding state:1
The port is in the portfast mode by portfast trunk configuration
Link type is point-to-point by default
Bpdu filter is enabled
Loop guard is enabled by default on the port
BPDU:sent 0, received 0
To enable loop guard on a port, perform this task:
OL-4266-08
Purpose
1
Selects a port to configure.
slot/port } |
Enables root guard.
Disables root guard.
Exits configuration mode.
Verifies the configuration.
1
slot/port } |
Purpose
Enables loop guard globally on the router.
Exits configuration mode.
Verifies the configuration impact on a port.
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
End with CNTL/Z.
Enabling Loop Guard
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