Refer to the exhibit.

BFD is not required for the specific failure described: a physical fiber break on point-to-point routed links. In a Layer 3 campus or routed-access design, a direct physical link failure is detected by the interface state change, so the routing protocol can react immediately without waiting for hello/dead timers. Cisco campus design guidance favors point-to-point routed links partly because they give rapid convergence and avoid STP delays. BFD is valuable when a forwarding-path failure is not reliably detected by Layer 1 or Layer 2, or when a protocol adjacency must detect loss faster than its native timers. It does not automatically create convergence by itself; it detects failure and notifies the routing protocol. For a clean fiber cut on a routed point-to-point link, link-down detection is already fast enough for sub-second failover in the design. OSPF timer tuning is also not the preferred design answer for this physical-failure case. Reference topics: routed access design, point-to-point links, link-failure detection, BFD, OSPF convergence.