Concept Guide
ROUTER-ISIS mode
no bfd all-neighbors
• Disable BFD sessions with IS-IS neighbors on a single interface.
INTERFACE mose
isis bfd all-neighbors disable
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 physical, port-channel, and VLAN
interfaces. BFD for BGP does not support the BGP multihop feature.
Before conguring BFD for BGP, you must rst congure BGP on the routers that you want to interconnect.
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:
• By establishing BFD sessions with all neighbors discovered by BGP (the bfd all-neighbors command).
• By establishing a BFD session with a specied BGP neighbor (the neighbor {ip-address | peer-group-name} bfd
command)
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Bidirectional Forwarding Detection (BFD)