OpenBFDD is an open source package that provides a software based
implantation of the Bidirectional Forwarding Detection (BFD) protocol. It
is designed to run on a server. Its primary purpose is to allow the
administrator to quickly take the server off-line when the core service,
such as a bind or unbound server, goes down. This is done by providing a
BFD "beacon", bfdd-beacon, that can communicate with a properly
configured, BFD enabled, router. A control utility, bfdd-control, can be
used to configure the running bfdd-beacon daemon, and to change the state
of its BFD sessions.