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Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
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Chapter 32 Configuring UDLD
Default UDLD Configuration
Default UDLD Configuration
Table 32-1 shows the default UDLD configuration.
Configuring UDLD
These sections describe how to configure UDLD:
Enabling UDLD Globally, page 32-3
Enabling UDLD on Individual LAN Interfaces, page 32-4
Disabling UDLD on Fiber-Optic LAN Interfaces, page 32-5
Configuring the UDLD Probe Message Interval, page 32-5
Resetting Disabled LAN Interfaces, page 32-6
Note With Release 12.1(11b)E and later releases, when you are in configuration mode you can enter EXEC
mode-level commands by entering the do keyword before the EXEC mode-level command.

Enabling UDLD Globally

To enable UDLD globally on all fiber-optic LAN ports, perform this task:
Table 32-1 UDLD Default Configuration
Feature Default Value
UDLD global enable state Globally disabled
UDLD aggressive mode Disabled
UDLD per-port enable state for fiber-optic media Enabled on all Ethernet fiber-optic LAN ports
UDLD per-port enable state for twisted-pair (copper) media Disabled on all Ethernet 10/100 and 1000BASE-TX LAN
ports
Command Purpose
Router(config)# udld {enable | aggressive} Enables UDLD globally on fiber-optic LAN ports.
Note This command only configures fiber-optic LAN ports.
Individual LAN port configuration overrides the
setting of this command.
Router(config)# no udld {enable | aggressive} Disables UDLD globally on fiber-optic LAN ports.