Reference Guide

Bidirectional Forwarding Detection (BFD) | 181
Troubleshooting BFD
Examine control packet field values using the command debug bfd detail. The following example shows a
three-way handshake using this command.
Figure 8-29. debug bfd detail Command Output
Examine control packets in hexadecimal format using the command debug bfd packet.
Figure 8-30. debug bfd packet Command Output
The output for the command debug bfd event is the same as the log messages that appear on the console by
default.
FTOS(conf-if-te-4/24)#00:54:38: %STKUNIT3-M:CP %BFDMGR-1-BFD_STATE_CHANGE: Changed
session state to Down for neighbor 2.2.2.2 on interface Te 4/24 (diag: 0)
00:54:38 : Sent packet for session with neighbor 2.2.2.2 on Te 4/24
TX packet dump:
Version:1, Diag code:0, State:Down, Poll bit:0, Final bit:0, Demand bit:0
myDiscrim:4, yourDiscrim:0, minTx:1000000, minRx:1000000, multiplier:3,
minEchoRx:0
00:54:38 : Received packet for session with neighbor 2.2.2.2 on Te 4/24
RX packet dump:
Version:1, Diag code:0, State:Init, Poll bit:0, Final bit:0, Demand bit:0
myDiscrim:6, yourDiscrim:4, minTx:1000000, minRx:1000000, multiplier:3,
minEchoRx:0
00:54:38: %STKUNIT3-M:CP %BFDMGR-1-BFD_STATE_CHANGE: Changed session state to Up for
neighbor 2.2.2.2 on interface Te 4/24 (diag: 0)
RX packet dump:
20 c0 03 18 00 00 00 05 00 00 00 04 00 01 86 a0
00 01 86 a0 00 00 00 00
00:34:13 : Sent packet for session with neighbor 2.2.2.2 on Te 4/24
TX packet dump:
20 c0 03 18 00 00 00 04 00 00 00 05 00 01 86 a0
00 01 86 a0 00 00 00 00
00:34:14 : Received packet for session with neighbor 2.2.2.2 on Te 4/24
RX packet dump:
20 c0 03 18 00 00 00 05 00 00 00 04 00 01 86 a0
00 01 86 a0 00 00 00 00
00:34:14 : Sent packet for session with neighbor 2.2.2.2 on Te 4/24
TX packet dump: