Troubleshooting Bfd - Dell S4820T Configuration Manual

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
Examples of Output from the debug bfd Commands
The following example shows a three-way handshake using the debug bfd detail command.
R1(conf-if-te-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 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: %RPM0-P:RP2 %BFDMGR-1-BFD_STATE_CHANGE: Changed session state to
Up for neighbor 2.2.2.2
on interface Te 4/24 (diag: 0)
The following example shows 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 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:
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
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Bidirectional Forwarding Detection (BFD)
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