How would you describe a route that is considered a feasible successor in EIGRP?

A feasible successor in EIGRP (Enhanced Interior Gateway Routing Protocol) is defined as a backup route that can be used if the primary route fails. To qualify as a feasible successor, the route's reported distance must be less than the feasible distance of the primary route. The feasible distance is the lowest calculated metric to reach a destination, while the reported distance is the metric advertised by a neighboring router.

When a neighboring router provides a route via the EIGRP protocol, and that route has a reported distance that is lower than the feasible distance of the current best route, it can be considered a feasible successor. This characteristic allows EIGRP to efficiently switch over to the feasible successor quickly without needing to perform a full route recalculation.

For instance, if the primary route has a feasible distance of 100 and a neighbor advertises a route with a reported distance of 80, that route will be accepted as a feasible successor. This capability enhances the convergence speed and reliability of EIGRP by allowing immediate failover to the backup routes when needed.