Cisco Catalyst 2960-XR Configuration Manual page 115

Configuring Optional Spanning-Tree Features
You cannot enable both loop guard and root guard at the same time.
Note
You can enable this feature if your switch is running PVST+, Rapid PVST+, or MSTP.
This procedure is optional. Beginning in privileged EXEC mode, follow these steps to enable loop guard on
the switch.
SUMMARY STEPS
1. Enter one of the following commands:
2. configure terminal
3. spanning-tree loopguard default
4. end
DETAILED STEPS
Command or Action
Step 1 Enter one of the following commands:
• show spanning-tree active
• show spanning-tree mst
Example:
Switch# show spanning-tree active
or
Switch# show spanning-tree mst
Step 2 configure terminal
Example:
Switch# configure terminal
Step 3 spanning-tree loopguard default
Example:
Switch(config)# spanning-tree loopguard default
OL-29424-01
• show spanning-tree active
• show spanning-tree mst
Catalyst 2960-XR Switch Layer 2 Configuration Guide, Cisco IOS Release 15.0(2)EX1
Enabling Loop Guard
Purpose
Verifies which interfaces are alternate or root
ports.
Enters global configuration mode.
Enables loop guard.
By default, loop guard is disabled.
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