Cisco Catalyst 2960 Series User Manual

PurposeCommand or Action
Example:
Switch(config-if)# spanning-tree guard root
By default, root guard is disabled on all interfaces.
Returns to privileged EXEC mode.end
Example:
Switch(config-if)# end
Step 5
Related Topics
Root Guard, on page 297
Enabling Loop Guard
You can use loop guard to prevent alternate or root ports from becoming designated ports because of a failure
that leads to a unidirectional link. This feature is most effective when it is configured on the entire switched
network. Loop guard operates only on interfaces that are considered point-to-point by the spanning tree.
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. 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
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
313
How to Configure Optional Spanning-Tree Features

Cisco Catalyst 2960 Series Specifications

General

Layer	Layer 2
Power over Ethernet (PoE)	Available on some models
RAM	128 MB
Flash Memory	32 MB
MAC Address Table Size	8000
Operating Temperature	0°C to 45°C (32 to 113°F)
Ports	24 or 48 x 10/100/1000