KB.15.15

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 to 10.

Default: 5

Syntax

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

Assigns a VLAN ID to a UDLD-enabled port for sending tagged UDLD control packets.Under default

settings, untagged UDLD packets can still be transmitted and received on tagged only ports;

however, a warning message is logged.

The no form of the command disables UDLD on the specified ports.

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

packets

Enabling UDLD

UDLD is enabled on a per-port basis.

Example

To enable UDLD on port a1, enter:

(HP_Switch_name#) interface al link-keepalive

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

(HP_Switch_name#)interface al-a4 link-keepalive

NOTE: 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-UDLDconfigured 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.

Changing the keepalive interval

By default, ports enabled for UDLD send a link health-check packet once every 5 seconds. You

can change the interval to a value from 10 to 100 deciseconds, where 10 is 1 second, 11 is 1.1

seconds, and so on.

Example

To change the packet interval to seven seconds, enter the following command at the global

configuration level:

(HP_Switch_name#) link-keepalive interval 70

Changing the keepalive retries

By default, a port waits 5 seconds to receive a health-check reply packet from the port at the other

end of the link. If the port does not receive a reply, the port tries four more times by sending up to

four more health-check packets. If the port still does not receive a reply after the maximum number

of retries, the port goes down.

You can change the maximum number of keepalive attempts to a value from 3 to 10.

98 Port Status and Configuration