Udld - Cisco 300 Series Cli Manual

UDLD Commands
OL-32830-01 Command Line Interface Reference Guide

54.2 udld

Use the udld command in Global Configuration mode to globally enable the
UniDirectional Link Detection (UDLD) protocol. To disable UDLD, use the no form of
this command.
Syntax
udld aggressive | normal
no udld
Parameters
•
aggressive—Enables UDLD in aggressive mode by default on all fiber
interfaces.
•
normal—Enables UDLD in normal mode by default on all fiber interfaces.
Default Configuration
UDLD is disabled on all fiber interfaces.
Command Mode
Global Configuration mode
User Guidelines
This command affects fiber interfaces only. Use the udld port command in
Interface Configuration mode to enable UDLD on other interface types.
Use the no form of this command to disable UDLD on all fiber ports.
The device supports the UDLD protocol specified by RFC 5171.
UDLD supports two modes of operation: normal and aggressive. In the aggressive
mode the device shuts down a port if it cannot explicitly detect that the link is
bidirectional. In the normal mode the device shuts down an interface if it explicitly
detect that the link is unidirectional. A unidirectional link occurs whenever traffic
sent by a local device is received by its neighbor but traffic from the neighbor is
not received by the local device.
You can use the following commands to reset an interface shut down by UDLD:
•
The errdisable recover reset command with the interface
parameter to reset a given interface.
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interface-id
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