Cisco Catalyst 3550 Command Reference Manual page 515

Chapter 2 Catalyst 3550 Switch Cisco IOS Commands
Switch# show udld gigabitethernet0/1
Interface Gi0/1
---
Port enable administrative configuration setting:Enabled / in aggressive mode
Port enable operational state:Enabled / in aggressive mode
Current bidirectional state:Unknown
Current operational state:Link down
Message interval:7
Time out interval:5
No neighbor cache information stored
Related Commands Command
udld
udld port
udld reset
OL-8566-01
Description
Enables aggressive or normal mode in UDLD or sets the
configurable message timer time.
Enables UDLD on an individual interface or prevents a fiber-optic
interface from being enabled by the udld global configuration
command.
Resets all interfaces shutdown by UDLD and permits traffic to begin
passing through them again.
Catalyst 3550 Multilayer Switch Command Reference
show udld
2-489