24-6
Catalyst 2960 and 2960-S Switch Software Configuration Guide
OL-8603-09
Chapter 24 Configuring UDLD
Configuring UDLD
Enabling UDLD on an Interface
Beginning in privileged EXEC mode, follow these steps either to enable UDLD in the aggressive or
normal mode or to disable UDLD on a port:
Resetting an Interface Disabled by UDLD
Beginning in privileged EXEC mode, follow these steps to reset all ports disabled by UDLD:
You can also bring up the port by using these commands:
The shutdown interface configuration command followed by the no shutdown interface
configuration command restarts the disabled port.
The no udld {aggressive | enable} global configuration command followed by the udld
{aggressive | enable} global configuration command re-enables the disabled ports.
The no udld port interface configuration command followed by the udld port [aggressive]
interface configuration command re-enables the disabled fiber-optic port.
The errdisable recovery cause udld global configuration command enables the timer to
automatically recover from the UDLD error-disabled state, and the errdisable recovery interval
interval global configuration command specifies the time to recover from the UDLD error-disabled
state.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface interface-id Specify the port to be enabled for UDLD, and enter interface
configuration mode.
Step 3 udld port [aggressive] UDLD is disabled by default.
Note When a switch joins a switch stack, it retains its
interface-specific UDLD settings.
udld port—Enables UDLD in normal mode on the specified port.
udld port aggressive—Enables UDLD in aggressive mode on the
specified port.
Note Use the no udld port interface configuration command to
disable UDLD on a specified fiber-optic port.
For more information about aggressive and normal modes, see the
“Modes of Operation” section on page 24-1.
Step 4 end Return to privileged EXEC mode.
Step 5 show udld interface-id Verify your entries.
Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Step 1 udld reset Reset all ports disabled by UDLD.
Step 2 show udld Verify your entries.