Administrator Guide
Congure BFD for BGP
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, port-channel, and VLAN
interfaces. BFD for BGP does not support IPv6 and the BGP multihop feature.
Prerequisites
Before conguring BFD for BGP, you must rst congure the following settings:
1 Congure BGP on the routers that you want to interconnect, as described in Border Gateway Protocol IPv4 (BGPv4).
2 Enable fast fall-over for BGP neighbors to reduce convergence time (the neighbor fall-over command), as described in BGP
Fast Fall-Over.
Establishing Sessions with BGP Neighbors
Before conguring BFD for BGP, you must rst congure BGP on the routers that you want to interconnect.
For more information, refer to Border Gateway Protocol IPv4 (BGPv4).
For example, the following illustration shows a sample BFD conguration on Router 1 and Router 2 that use eBGP in a transit network to
interconnect AS1 and AS2. The eBGP routers exchange information with each other as well as with iBGP routers to maintain connectivity
and accessibility within each autonomous system.
Figure 15. Establishing Sessions with BGP Neighbors
The sample conguration shows alternative ways to establish a BFD session with a BGP neighbor:
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Bidirectional Forwarding Detection (BFD)