System information

10-44
Port Status and Basic Configuration
Uni-Directional Link Detection (UDLD)
Changing the Keepalive Retries
By default, a port waits five 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 – 10. For example, to change the maximum number of attempts to 4, enter
the following command at the global configuration level:
ProCurve(config)# link-keepalive retries 4
Configuring UDLD for Tagged Ports
The default implementation of UDLD sends the UDLD control packets
untagged, even across tagged ports. If an untagged UDLD packet is received
by a non-ProCurve switch, that switch may reject the packet. To avoid such
an occurrence, you can configure ports to send out UDLD control packets that
are tagged with a specified VLAN.
To enable ports to receive and send UDLD control packets tagged with a
specific VLAN ID, enter a command such as the following at the interface
configuration level:
Notes ■ You must configure the same VLANs that will be used for UDLD on
all devices across the network; otherwise, the UDLD link cannot be
maintained.
■ If a VLAN ID is not specified, then UDLD control packets are sent out
of the port as untagged packets.
■ To re-assign a VLAN ID, re-enter the command with the new VLAN ID
number. The new command will overwrite the previous command
setting.
■ When configuring UDLD for tagged ports, you may receive a warning
message if there are any inconsistencies with the port’s VLAN config-
uration (see page 47 for potential problems).
ProCurve(config)#interface l link-keepalive vlan 22