Cisco ME 3600X, Command Reference Manual

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Cisco ME 3800X and ME 3600X Switch Command Reference
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Chapter
udld
udld
To enable aggressive or normal mode in the UniDirectional Link Detection (UDLD) and to set the
configurable message timer, use the
udld command in global configuration mode. To disable aggressive
or normal mode UDLD on all fiber-optic ports, use the no form of the command.
udld { aggressive | enable | message time message-timer-interval }
no udld { aggressive | enable | message }
Syntax Description
Defaults UDLD is disabled on all interfaces.
The message timer is set at 60 seconds.
Command Modes Global configuration
Command History
Usage Guidelines
UDLD supports two modes of operation: normal (the default) and aggressive. In normal mode, UDLD
detects unidirectional links due to misconnected interfaces on fiber-optic connections. In aggressive
mode, UDLD also detects unidirectional links due to one-way traffic on fiber-optic and twisted-pair links
and due to misconnected interfaces on fiber-optic links. For information about normal and aggressive
modes, see the “Understanding UDLD” section in the software configuration guide for this release.
If you change the message time between probe packets, you are making a trade-off between the detection
speed and the CPU load. By decreasing the time, you can make the detection-response faster but increase
the load on the CPU.
This command affects fiber-optic interfaces only. Use the udld interface configuration command to
enable UDLD on other interface types.
You can use these commands to reset an interface shut down by UDLD:
• The udld reset privileged EXEC command to reset all interfaces shut down by UDLD
•
The shutdown and no shutdown interface configuration commands
• The no udld enable global configuration command followed by the udld { aggressive | enable }
global configuration command to re-enable UDLD globally
aggressive Enables UDLD in aggressive mode on all fiber-optic interfaces.
enable Enables UDLD in normal mode on all fiber-optic interfaces.
message time
message-timer-interval
Configures the period of time between UDLD probe messages on ports that
are in the advertisement phase and are determined to be bidirectional. The
range is 7 to 90 seconds.
Release Modification
12.2(52)EY This command was introduced.