Specifications

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Catalyst 2950 and Catalyst 2955 Switch Command Reference
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Chapter 2 Cisco IOS Commands
udld (interface configuration)
Use the no udld enable command on fiber-optic ports to return control of UDLD to the udld enable
global configuration command or to disable UDLD on nonfiber-optic ports.
Use the udld aggressive command on fiber-optic ports to override the settings of the udld enable or
udld aggressive global configuration command. Use the no form on fiber-optic ports to remove this
setting and to return control of UDLD enabling to the udld global configuration command or to disable
UDLD on nonfiber-optic ports.
The disable keyword is supported on fiber-optic ports only. Use the no form of this command to remove
this setting and to return control of UDLD to the udld global configuration command.
If the switch software detects a GBIC module change and the interface changes from fiber optic to
nonfiber optic or from nonfiber optic to fiber optic, all configurations are maintained.
Examples This example shows how to enable UDLD on an interface:
Switch(config)# interface fastethernet0/2
Switch(config-if)# udld enable
This example shows how to disable UDLD on a fiber-optic interface despite the setting of the udld
global configuration command:
Switch(config)# interface gigabitethernet0/2
Switch(config-if)# udld disable
You can verify your settings by entering the show running-config or show udld privileged EXEC
command.
Related Commands Command Description
show running-config Displays the running configuration on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
show udld Displays UDLD status for all ports or the specified port.
udld (global configuration) Enables UDLD on all fiber-optic ports on the switch.
udld reset Resets all interfaces shut down by UDLD and permits traffic to
again pass through.