http://www.rfc-editor.org/rfc/rfc7881.txt
RFC 7881: Seamless Bidirectional Forwarding Detection (S-BFD) for IPv4, IPv6, and MPLS, C. Pignataro, D. Ward, N. Akiya2016-07-01T23:00:00-00:00This document defines procedures for using Seamless Bidirectional Forwarding Detection (S-BFD) in IPv4, IPv6, and MPLS environments.