BFD interworking includes static and dynamic BFD interworking. Static BFD interworking refers to interworking between BFD and hot standby, static route, policy-based routing (PBR), and DHCP. Dynamic BFD interworking refers to interworking between BFD and RIP, OSPF, OSPFv3, BGP, and BGP4+. BFD and IS-IS can carry out either static or dynamic interworking.