Administrator Guide

• Configure BFD for IS-IS
• Configure BFD for BGP
• Configure BFD for VRRP
• Configuring Protocol Liveness
• Troubleshooting BFD
Configure BFD for Physical Ports
Configuring 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 local system does not remove the connected route until the first failed attempt to send a
packet. When you enable BFD, the local system removes 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 Globally
You 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 mode
bfd enable
Example of Verifying BFD is Enabled
To 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 protocol
protocol-liveness Enable BFD protocol-liveness
R1(conf)#bfd enable
R1(conf)#do show running-config bfd
!
bfd enable
R1(conf)#
Bidirectional Forwarding Detection (BFD)
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