Bidirectional Forwarding Detection (Paperback)

High Quality Content by WIKIPEDIA articles! Bidirectional Forwarding Detection (BFD) is a network protocol used to detect faults between two forwarding engines connected by a link. It provides low-overhead detection of faults even on physical media that don't support failure detection of any kind, such as Ethernet, virtual circuits, tunnels and MPLS Label Switched Paths. BFD establishes a session between two endpoints over a particular link. If more than one link exists between two systems, multiple BFD sessions may be established to monitor each one of them. The session is established with a three-way handshake, and is torn down the same way. Authentication may be enabled on the session. A choice of simple password, MD5 or SHA1 authentication is available.