China Unicom China Unicom China Unicom This document specifies the use of Bidirectional Forwarding Detection (BFD) for fast failure detection of Routing in Fat Trees (RIFT) adjacencies. RIFT is specified in RFC 9692. While RFC 9692 describes interactions with BFD, it does not define normative behavior. This document specifies the use of single-hop BFD, as defined in RFC 5881, for RIFT adjacencies, including behavior for parallel links and multiple RIFT instances.