System information

10-43
Port Status and Basic Configuration
Uni-Directional Link Detection (UDLD)
Enabling UDLD
UDLD is enabled on a per port basis. For example, to enable UDLD on port
a1, enter:
To enable the feature on a trunk group, enter the appropriate port range. For
example:
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-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.
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 – 100 deciseconds,
where 10 is 1 second, 11 is 1.1 seconds, and so on. For example, to change the
packet interval to seven seconds, enter the following command at the global
configuration level:
ProCurve(config)# link-keepalive interval 70
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
ProCurve(config)#interface al link-keepalive
ProCurve(config)#interface al-a4 link-keepalive