Udld (Interface Configuration Mode) - Cisco Catalyst 4500 Series Command Reference Manual

udld (interface configuration mode)

udld (interface configuration mode)
To enable UDLD and Fast UDLD on an individual interface or to prevent a fiber-optic interface from
being enabled by the
Use the no form of this command to disable UDLD, or to return a nonfiber port to the setting specified
with the
Syntax Description aggressive
disable
fast-hello
interval
Defaults
The fiber-optic interfaces are enabled with the state of the global udld (enable or aggressive) command.
The nonfiber interfaces are enabled with UDLD disabled.
Fast UDLD is disabled.
Command Modes Interface configuration
Command History Release
12.1(8a)EW
12.2(54)SG
Usage Guidelines If you enable aggressive mode, once all the switch port's neighbors have aged out either in the
advertisement or in the detection phase, UDLD and Fast UDLD restart the linkup sequence. They can
resynchronize with any potentially out-of-sync neighbor and shut down the port if the UDLD messages
from the neighbor indicate that the link state is still undetermined
Use the udld port aggressive command on fiber-optic ports to override the setting of the global udld (enable
or aggressive) command. Use the no form of the command on fiber-optic ports to restore the UDLD state as
configured by the global udld command.
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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udld (global configuration mode)
udld (global configuration mode)
udld port {aggressive | disable}
no udld port {aggressive | disable}
udld fast-hello interval
no udld fast-hello
Enables UDLD in aggressive mode.
Disables UDLD.
Enables Fast UDLD with the configured timer.
Sets the timer interval.
Modification
Support for this command was introduced on the Catalyst 4500 series switch.
Support was added for Fast UDLD.
If udld enable is configured globally, UDLD is enabled on all fiber-optic interfaces in
nonaggressive mode. You can configure udld port aggressive on a fiber-optic interface to override
the udld enable command setting and to enter aggressive mode. If you enter the
no udld port aggresive command, the settings of the previous global state are reestablished and the
aggressive mode is removed.
Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
command, use the udld interface level command.
command.
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