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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter28 Configuring UDLD
Configuring UDLD
Enabling UDLD Globally
Beginning in privileged EXEC mode, follow these steps to enable UDLD in the aggressive or normal
mode and to set the configurable message timer on all fiber-optic ports on the switch and all members
in the switch stack:
To disable UDLD globally, use the no udld enable global configuration command to disable normal
mode UDLD on all fiber-optic ports. Use the no udld aggressive global configuration command to
disable aggressive mode UDLD on all fiber-optic ports.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 udld {aggressive | enable | message time
message-timer-interval}
Specify the UDLD mode of operation:
aggressive—Enables UDLD in aggressive mode on all fiber-optic
ports.
enable—Enables UDLD in normal mode on all fiber-optic ports on
the switch. UDLD is disabled by default.
An individual interface configuration overrides the setting of the
udld enable global configuration command.
For more information about aggressive and normal modes, see the
“Modes of Operation” section on page28-1.
message time message-timer-interval—Configures the period of
time between UDLD probe messages on ports that are in the
advertisement phase and are detected to be bidirectional. The range
is from 1 to 90 seconds. The default value is 15.
Note The global UDLD setting is automatically applied to switches
that join the switch stack.
Note This command affects fiber-optic ports only. Use the udld
interface configuration command to enable UDLD on other port
types. For more information, see the “Enabling UDLD on an
Interface” section on page 28-6.
Step3 end Return to privileged EXEC mode.
Step4 show udld Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.