Cisco Catalyst 2960 Software Configuration Manual page 509

Chapter 18 Configuring Optional Spanning-Tree Features
Beginning in privileged EXEC mode, follow these steps to enable loop guard. This procedure is optional.
Command
Step 1
show spanning-tree active
or
show spanning-tree mst
Step 2 configure terminal
Step 3 spanning-tree loopguard default
Step 4 end
Step 5
show running-config
Step 6 copy running-config startup-config
To globally disable loop guard, use the no spanning-tree loopguard default global configuration
command. You can override the setting of the no spanning-tree loopguard default global configuration
command by using the spanning-tree guard loop interface configuration command.
Displaying the Spanning-Tree Status
To display the spanning-tree status, use one or more of the privileged EXEC commands in
Table 18-2 Commands for Displaying the Spanning-Tree Status
Command
show spanning-tree active
show spanning-tree detail
show spanning-tree interface interface-id
show spanning-tree mst interface interface-id
show spanning-tree summary [totals]
You can clear spanning-tree counters by using the clear spanning-tree [interface interface-id]
privileged EXEC command.
For information about other keywords for the show spanning-tree privileged EXEC command, see the
command reference for this release.
OL-26520-01
Purpose
Verify which interfaces are alternate or root ports.
Enter global configuration mode.
Enable loop guard.
By default, loop guard is disabled.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Purpose
Displays spanning-tree information on active interfaces only.
Displays a detailed summary of interface information.
Displays spanning-tree information for the specified interface.
Displays MST information for the specified interface.
Displays a summary of interface states or displays the total lines of the
spanning-tree state section.
Catalyst 2960 and 2960-S Switches Software Configuration Guide, Release 15.0(1)SE
Displaying the Spanning-Tree Status
Table
18-19
18-2: