Cisco Catalyst 2960-XR Configuration Guide

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:
•
show spanning-tree active
•
show spanning-tree mst
2.
configure terminal
3.
spanning-tree loopguard default
4.
end
DETAILED STEPS
PurposeCommand or Action
Verifies which interfaces are alternate or root
ports.
Enter one of the following commands:
Step 1
•
show spanning-tree active
•
show spanning-tree mst
Example:
Switch# show spanning-tree active
or
Switch# show spanning-tree mst
Enters global configuration mode.configure terminal
Example:
Switch# configure terminal
Step 2
Enables loop guard.spanning-tree loopguard default
Step 3
Example:
Switch(config)# spanning-tree loopguard default
By default, loop guard is disabled.
Catalyst 2960-XR Switch Layer 2 Configuration Guide, Cisco IOS Release 15.0(2)EX1
OL-29424-01 101
Configuring Optional Spanning-Tree Features
Enabling Loop Guard

Cisco Catalyst 2960-XR Specifications

General

Stacking Bandwidth	80 Gbps
Layer Support	Layer 2 and Layer 3
Jumbo Frame Support	9198 bytes
RAM	512 MB
Input Voltage	100-240V AC
Model	Catalyst 2960-XR
Uplink Interfaces	4 x 1G SFP or 2 x 10G SFP+
Downlink Interfaces	24 or 48 x Gigabit Ethernet ports
Power Supply	Internal
MAC Address Table Size	16, 000 entries
PoE	Available on PoE models
Weight	4.5 kg
Features	energy efficiency
Stacking	Up to 8 switches
Operating Temperature	0 to 45°C