Reference Guide

Table Of Contents
Configuring Protocol Liveness
Protocol liveness is a feature that notifies the BFD manager when a client protocol is disabled.
When you disable a client, all BFD sessions for that protocol are torn down. Neighbors on the remote
system receive an Admin Down control packet and are placed in the Down state.
To enable protocol liveness, use the following command.
Enable Protocol Liveness.
CONFIGURATION mode
bfd protocol-liveness
Troubleshooting BFD
To troubleshoot BFD, use the following commands and examples.
To control packet field values or to examine the control packets in hexadecimal format, use the following
command.
Examine control packet field values.
CONFIGURATION mode
debug bfd detail
Examine the control packets in hexadecimal format.
CONFIGURATION
debug bfd packet
Example of Output from the debug bfd detail Command
Example of Output from the debug bfd packet Command
The following example shows a three-way handshake using the debug bfd detail command.
Dell(conf-if-gi-4/24)#00:54:38: %RPM0-P:RP2 %BFDMGR-1-BFD_STATE_CHANGE:
Changed session state to
Down for neighbor 2.2.2.2 on interface Gi 4/24 (diag: 0)
00:54:38 : Sent packet for session with neighbor 2.2.2.2 on Gi 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 Gi 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: %RPM0-P:RP2 %BFDMGR-1-BFD_STATE_CHANGE:
Changed session state to
Up for neighbor 2.2.2.2
on interface Gi 4/24 (diag: 0)
The following example displays hexadecimal output from the debug bfd packet command.
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 Gi 4/24
178
Bidirectional Forwarding Detection (BFD)