BFD for IP Links
You can create a single-hop or multi-hop BFD session on an IP link to detect faults quickly:
Single-hop BFD detects IP connectivity of the forwarding link between two directly connected systems.
Multi-hop BFD detects IP connectivity of paths between two indirectly connected systems. These paths may span multiple hops or overlap.
Application
Typical application 1:
In Figure 1, a BFD session detects a single-hop path between two devices. The BFD session is bound to the outbound interface.
Typical application 2:
In Figure 2, a BFD session detects a multi-hop path between SwitchA and SwitchC. The BFD session is bound to the peer IP address, not the outbound interface.
