Bidirectional Forward Detection (BFD) Support for Cisco Integrated Services Routers BFD is a detection protocol that is designed to provide fast forwarding path failure detection times for all media types. It provides a low-overhead, short-duration method of detecting failures in the forwarding path between two adjacent routers, including the interfaces, data links, and forwarding planes. BFD delivers fast router peer failure detection times independent of all media types, encapsulations, topologies, and routing protocols including EIGRP, IS-IS, OSPF, and BGP (single-hop peers over Ethernet interfaces).