Enabling Loop Guard - Cisco 4500M Software Manual

Chapter 15 Configuring STP Features
Command
Step 3
Switch(config-if)# end
Step 4
Switch# show spanning-tree
This example shows how to enable root guard on Fast Ethernet interface 5/8:
Switch(config)# interface fastethernet 5/8
Switch(config-if)# spanning-tree guard root
Switch(config-if)# end
Switch#
This example shows how to verify the configuration:
Switch# show running-config interface fastethernet 5/8
Building configuration...
Current configuration: 67 bytes
!
interface FastEthernet5/8
switchport mode access
spanning-tree guard root
end
Switch#
This example shows how to determine whether any ports are in root inconsistent state:
Switch# show spanning-tree inconsistentports
Name
-------------------- ---------------------- ------------------
VLAN0001
VLAN0001
VLAN1002
VLAN1002
VLAN1003
VLAN1003
VLAN1004
VLAN1004
VLAN1005
VLAN1005
Number of inconsistent ports (segments) in the system :10

Enabling Loop Guard

You can enable loop guard globally or per port.
To enable loop guard globally on the switch, perform this task:
Command
Step 1
Switch(config)# spanning-tree loopguard default
Step 2
Switch(config)# end
Step 3
Switch# show spanning tree interface 4/4 detail
OL-6696-01
Purpose
Exits configuration mode.
Verifies the configuration.
Interface
FastEthernet3/1
FastEthernet3/2
FastEthernet3/1
FastEthernet3/2
FastEthernet3/1
FastEthernet3/2
FastEthernet3/1
FastEthernet3/2
FastEthernet3/1
FastEthernet3/2
Purpose
Enables loop guard globally on the switch.
Exits configuration mode.
Verifies the configuration impact on a port.
Software Configuration Guide—Release 12.2(25)EW
Inconsistency
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Port Type Inconsistent
Enabling Loop Guard
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