Reference Guide

150 | Bidirectional Forwarding Detection (BFD)
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View session parameters using the command show bfd neighbors detail.
Disabling BFD for IS-IS
If BFD is disabled globally, all sessions are torn down, and sessions on the remote system are placed in a
Down state. If BFD is disabled on an interface, sessions on the interface are torn down, and sessions on the
remote system are placed in a Down state (Message 4). Disabling BFD does not trigger a change in BFD
clients; a final Admin Down packet is sent before the session is terminated.
To disable BFD sessions with all IS-IS neighbors:
To disable BFD sessions with all IS-IS neighbors out of an interface:
Configuring BFD for BGP
BFD for BGP is only supported on platforms: e c
In a BGP core network, BFD provides rapid detection of communication failures in BGP fast-forwarding
paths between internal BGP (iBGP) and external BGP (eBGP) peers for faster network reconvergence.
BFD for BGP is supported on 1GE, 10GE, 40GE, port-channel, and VLAN interfaces. BFD for BGP does
not support IPv6 and the BGP multihop feature.
Prerequisites
Before configuring BFD for BGP, you must first configure the following settings:
1. Configure BGP on the routers that you want to interconnect as described in Chapter 9, Border
Gateway Protocol IPv4 (BGPv4).
2. Enable fast fall-over for BGP neighbors to reduce convergence time (
neighbor fall-over command) as
described in BGP fast fall-over.
Establishing sessions with BGP neighbors
Before configuring BFD for BGP, you must first configure BGP on the routers that you want to
interconnect. For more information, refer to Chapter 9, Border Gateway Protocol IPv4 (BGPv4).
Step Task Command Syntax Command Mode
1 Disable BFD sessions with all IS-IS
neighbors.
no bfd all-neighbors ROUTER-ISIS
Step Task Command Syntax Command Mode
1 Disable BFD sessions with all IS-IS
neighbors out of an interface.
isis bfd all-neighbors disable INTERFACE