Cisco Catalyst 4500 Series Software Configuration Manual page 744

About Detecting Unidirectional Link Failure
This example shows the interface details when a dispute condition is detected:
Switch# show spanning-tree interface gi3/13 detail
Port 269 (GigabitEthernet3/13) of VLAN0002 is designated blocking (dispute)
Port path cost 4, Port priority 128, Port Identifier 128.297.
Designated root has priority 32769, address 0013.5f20.01c0
Designated bridge has priority 32769, address 0013.5f20.01c0
Designated port id is 128.297, designated path cost 0
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 132, received 1
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
23-42
Chapter 23 Configuring STP and MST