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 multi-hop feature. In an OSPF core network, BFD can be configured to monitor and notify the reachability status between OSPF neighbors. When you use BFD with OSPF, BFD sessions are established between all neighboring interfaces participating with OSPF full state. If a neighboring interface fails, BFD notifies OSPF protocol that a link state change has occurred.
