Cisco Catalyst 4500 Series Software Configuration Manual page 924

Displaying UDLD Link Status
To verify status for a particular link as reported by Fast UDLD, enter the following command:
Switch# show udld fast-hello g1/33
Interface Gi1/33
---
Port enable administrative configuration setting: Enabled / in aggressive mode
Port enable operational state: Enabled / in aggressive mode
Current bidirectional state: Bidirectional
Current operational state: Advertisement - Single neighbor detected
Message interval: 200 ms
Time out interval: 5000 ms
Port fast-hello configuration setting: Enabled
Port fast-hello interval: 200 ms
Port fast-hello operational state: Enabled
Neighbor fast-hello configuration setting: Enabled
Neighbor fast-hello interval: 200 ms
Entry 1
---
Expiration time: 500 ms
Cache Device index: 1
Current neighbor state: Bidirectional
Device ID: FOX10430380
Port ID: Gi1/33
Neighbor echo 1 device: FOX104303NL
Neighbor echo 1 port: Gi1/33
TLV Message interval: 15
TLV fast-hello interval: 200 ms
TLV Time out interval: 5
TLV CDP Device name: Switch
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
33-10
Chapter 33 Configuring UDLD