3.1. Addressing and Session Establishment
A BFD session is established based on the needs of the application that will be making use of it. It is up to the application to determine the need for BFD, and the addresses to use -- there is no discovery mechanism in BFD. For example, an OSPF [OSPF] implementation may request a BFD session to be established to a neighbor discovered using the OSPF Hello protocol.