To disable all VRRP sessions on an interface, sessions for a particular VRRP group, or for a particular VRRP session on an interface, use thefollowing commands.• Disable all VRRP sessions on an interface.INTERFACE modeno vrrp bfd all-neighbors• Disable all VRRP sessions in a VRRP group.VRRP modebfd disable• Disable a particular VRRP session on an interface.INTERFACE modeno vrrp bfd neighbor ip-addressConfiguring Protocol LivenessProtocol 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 Downcontrol packet and are placed in the Down state.To enable protocol liveness, use the following command.• Enable Protocol Liveness.CONFIGURATION modebfd protocol-livenessTroubleshooting BFDTo 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 modedebug bfd detail• Examine the control packets in hexadecimal format.CONFIGURATIONdebug bfd packetExamples of Output from the debug bfd CommandsThe following example shows a three-way handshake using the debug bfd detail command.R1(conf-if-te-4/24/1)#00:54:38: %RPM0-P:RP2 %BFDMGR-1-BFD_STATE_CHANGE: Changed sessionstate toDown for neighbor 2.2.2.2 on interface Te 4/24/1 (diag: 0)00:54:38 : Sent packet for session with neighbor 2.2.2.2 on Te 4/24/1TX packet dump:Version:1, Diag code:0, State:Down, Poll bit:0, Final bit:0, Demand bit:0myDiscrim:4, yourDiscrim:0, minTx:1000000, minRx:1000000, multiplier:3, minEchoRx:000:54:38 : Received packet for session with neighbor 2.2.2.2 on Te 4/24/1RX packet dump:Version:1, Diag code:0, State:Init, Poll bit:0, Final bit:0, Demand bit:0myDiscrim:6, yourDiscrim:4, minTx:1000000, minRx:1000000, multiplier:3, minEchoRx:0Bidirectional Forwarding Detection (BFD) 161
