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Catalyst 3750 Metro Switch Command Reference
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Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
udld (global configuration)
udld (global configuration)
Use the
udld
global configuration command to enable aggressive or normal mode in the UniDirectional
Link Detection (UDLD) and to set the configurable message timer time. Use the
no
form of the command
to disable aggressive or normal mode UDLD on all fiber-optic ports.
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
can detect unidirectional links due to misconnected ports on fiber-optic connections. In aggressive mode,
UDLD also can detect unidirectional links due to one-way traffic on fiber-optic and twisted-pair links
and due to misconnected ports 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 only affects fiber-optic ports. 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.
aggressive
Enable UDLD in aggressive mode on all fiber-optic ports.
enable
Enable UDLD in normal mode on all fiber-optic ports.
message time
message-timer-interval
Configure the period of time between UDLD probe messages on interfaces
that are in the advertisement phase and are detected to be bidirectional. The
range is 1 to 90 seconds.
Release
Modification
12.1(14)AX
This command was introduced.
12.2(25)EY2
The range for message-timer-interval was changed from 7 to 90 seconds to
1 to 90 seconds.
