• Configure BFD for IS-IS• Configure BFD for BGP• Configure BFD for VRRP• Configuring Protocol Liveness• Troubleshooting BFDConfigure BFD for Physical PortsConfiguring BFD for physical ports is supported on the C-Series and E-Series platforms only.BFD on physical ports is useful when you do not enable the routing protocol. Without BFD, if the remote system fails, the localsystem does not remove the connected route until the first failed attempt to send a packet. When you enable BFD, the local systemremoves the route as soon as it stops receiving periodic control packets from the remote system.Configuring BFD for a physical port is a two-step process:1. Enable BFD globally.2. Establish a session with a next-hop neighbor.Related Configuration Tasks• Viewing Physical Port Session Parameters.• Disabling and Re-Enabling BFD.Enabling BFD GloballyYou must enable BFD globally on both routers.For more information about enabling BFD globally, refer to Establishing a Session on Physical Ports.To enable the BFD globally, use the following command.• Enable BFD globally.CONFIGURATION modebfd enableExample of Verifying BFD is EnabledTo verify that BFD is enabled globally, use the show running bfd command.The bold line shows that BFD is enabled.R1(conf)#bfd ?enable Enable BFD protocolprotocol-liveness Enable BFD protocol-livenessR1(conf)#bfd enableR1(conf)#do show running-config bfd!bfd enableR1(conf)#148 Bidirectional Forwarding Detection (BFD)
