Administrator Guide

BGP version 4, remote router ID 12.0.0.4
BGP state ESTABLISHED, in this state for 00:05:33
...
Neighbor is using BGP neighbor mode BFD configuration
Peer active in peer-group outbound optimization
...
R2# show ip bgp neighbors 2.2.2.4
BGP neighbor is 2.2.2.4, remote AS 1, external link
Member of peer-group pg1 for session parameters
BGP version 4, remote router ID 12.0.0.4
BGP state ESTABLISHED, in this state for 00:05:33
...
Neighbor is using BGP peer-group mode BFD configuration
Peer active in peer-group outbound optimization
...
Conguring Protocol Liveness
Protocol liveness is a feature that noties 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 eld values or to examine the control packets in hexadecimal format, use the following command.
• Examine control packet eld 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
Bidirectional Forwarding Detection (BFD)
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