15-10
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 15 Configuring Optional Spanning-Tree Features
Displaying the Spanning-Tree Status
You can enable this feature if your switch is running PVST+, rapid PVST+, or MSTP.
Beginning in privileged EXEC mode, follow these steps to enable loop guard. This procedure is optional.
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 on an NNI.
Displaying the Spanning-Tree Status
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.
Command
Purpose
Step 1
show spanning-tree active
or
show spanning-tree mst
Verify which interfaces are alternate or root ports.
Step 2
configure terminal
Enter global configuration mode.
Step 3
spanning-tree loopguard default
Enable loop guard. By default, loop guard is disabled.
Step 4
end
Return to privileged EXEC mode.
Step 5
show running-config
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Table 15-2
Commands for Displaying the Spanning-Tree Status
Command
Purpose
show spanning-tree active
Displays spanning-tree information on active interfaces only.
show spanning-tree detail
Displays a detailed summary of interface information.
show spanning-tree interface interface-id
Displays spanning-tree information for the specified interface.
show spanning-tree mst interface interface-id
Displays MST information for the specified interface.
show spanning-tree summary [totals]
Displays a summary of interface states or displays the total lines of the
spanning-tree state section.
