Users Guide

Table Of Contents
BFD for BGP
In a BGP core network, BFD enables faster network reconvergence. BFD rapidly detects communication failures in BGP fast-
forwarding paths between internal BGP (iBGP) and external BGP (eBGP) peers. BFD for BGP is supported on physical, port-
channel, and VLAN interfaces. BFD for BGP does not support the BGP multihop feature.
Before configuring BFD for BGP, first configure BGP on the interconnecting routers. For more information, see Border Gateway
Protocol.
BFD for BGP example
In this BFD for BGP configuration example, Router 1 and Router 2 use eBGP in a transit network to interconnect AS1 and AS2.
The eBGP routers exchange information with each other and with iBGP routers to maintain connectivity and accessibility within
each autonomous system.
When you configure a BFD session with a BGP neighbor, you can:
Establish a BFD session with a specified BGP neighbor using the neighbor ip-address and bfd commands.
Establish BFD sessions with all neighbors discovered by BGP using the bfd all-neighbors command.
For example:
Router 1
OS10(conf)# bfd enable
OS10(conf)# router bgp 1
OS10(config-router-bgp-1)# neighbor 2.2.4.3
OS10(config-router-neighbor)# bfd
OS10(config-router-neighbor)# no shutdown
OR
OS10(conf)# bfd enable
OS10(conf)# router bgp 1
OS10(config-router-bgp-1)# bfd all-neighbors interval 200 min_rx 200 multiplier 6 role
active
Router 2
OS10(conf)# bfd enable
OS10(conf)# router bgp 2
OS10(config-router-bgp-2)# neighbor 2.2.4.2
OS10(config-router-neighbor)# bfd
OS10(config-router-neighbor)# no shutdown
OR
OS10(conf)# bfd enable
OS10(conf)# router bgp 2
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Layer 3