Port Status and Configuration

Uni-Directional Link Detection (UDLD)

Syntax: link-keepalive interval <interval>

Determines the time interval to send UDLD control packets. The <interval> parameter specifies how often the ports send a UDLD packet. You can specify from 10 – 100, in 100 ms increments, where 10 is 1 second, 11 is 1.1 seconds, and so on.

Default: 50 (5 seconds)

Syntax: link-keepalive retries <num>

Determines the maximum number of retries to send UDLD control packets. The <num> parameter specifies the maximum number of times the port will try the health check. You can specify a value from 3 – 10.

Default: 5

Syntax: [no] interface <port-list> link-keepalive vlan <vid>

Assigns a VLAN ID to a UDLD-enabled port for sending of tagged UDLD control packets.Under default settings, untagged UDLD packets can still be transmitted and received on tagged only ports—however, a warning message will be logged.

The no form of the command disables UDLD on the specified port(s).

Default: UDLD packets are untagged; tagged only ports will transmit and receive untagged UDLD control packets

 

Enabling UDLD

 

UDLD is enabled on a per port basis. For example, to enable UDLD on port

 

a1, enter:

 

ProCurve(config)#interface al link-keepalive

 

To enable the feature on a trunk group, enter the appropriate port range. For

 

example:

 

ProCurve(config)#interface al-a4 link-keepalive

 

 

N o t e

When at least one port is UDLD-enabled, the switch will forward out UDLD

 

packets that arrive on non-UDLD-configured ports out of all other non-UDLD-

 

configured ports in the same vlan. That is, UDLD control packets will “pass

 

through” a port that is not configured for UDLD. However, UDLD packets will

 

be dropped on any blocked ports that are not configured for UDLD.

 

 

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