20-18
Catalyst 3750 Switch Software Configuration Guide
OL-8550-02
Chapter 20 Configuring Optional Spanning-Tree Features
Configuring Optional Spanning-Tree Features
Beginning in privileged EXEC mode, follow these steps to enable root guard on an interface. This
procedure is optional.
To disable root guard, use the
no spanning-tree guard
interface configuration command.
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.
Note
You cannot enable both loop guard and root guard at the same time.
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.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface
interface-id
Specify an interface to configure, and enter interface configuration mode.
Step 3
spanning-tree guard root
Enable root guard on the interface.
By default, root guard is disabled on all interfaces.
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.
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.
Содержание 3750G - Catalyst Integrated Wireless LAN Controller
Страница 80: ...1 28 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 1 Overview Where to Go Next ...
Страница 606: ...27 8 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 27 Configuring UDLD Displaying UDLD Status ...
Страница 670: ...31 18 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 31 Configuring SNMP Displaying SNMP Status ...
Страница 1048: ...41 20 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 41 Configuring MSDP Monitoring and Maintaining MSDP ...
Страница 1086: ...43 26 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 43 Troubleshooting Using the crashinfo Files ...
Страница 1104: ...B 4 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Appendix B Supported MIBs Using FTP to Access the MIB Files ...