In a network routing context, what does the term "feasible successor" refer to?

The term "feasible successor" is specific to the Enhanced Interior Gateway Routing Protocol (EIGRP). Within this context, a feasible successor represents a backup route that has been determined to be a viable candidate for immediate use when the primary route fails. EIGRP uses a concept called the "Successor" to track the primary route to a destination. When the primary route is deemed unreachable, the feasible successor can be quickly activated without needing to undergo the process of route recalculation or convergence, which enhances network reliability and reduces downtime. This immediate availability and readiness to be used makes the feasible successor an essential component of EIGRP's efficient routing capabilities.

The other definitions do not accurately describe this concept within routing protocols; thus, understanding this specific function of the feasible successor clarifies its importance in maintaining network efficiency and resilience.