Which type of EIGRP route is a backup route with a higher metric than the successor route?

The type of EIGRP route that serves as a backup route with a higher metric than the successor route is known as a Feasible Successor. In Enhanced Interior Gateway Routing Protocol (EIGRP), the successor route is the primary route to a network destination, with the lowest metric. The feasible successor is a backup route that can be immediately used if the successor becomes unavailable, allowing for quick convergence and better network resilience.

A feasible successor must meet certain conditions: it must be loop-free, and its reported distance must be less than the feasible distance of the active successor route. This relationship ensures that in case the primary route fails, EIGRP can switch to using the feasible successor without needing to recompute the entire routing table, thus maintaining network stability and performance.

In contrast, the other options represent different concepts or states within EIGRP that do not specifically refer to the backup nature of a feasible successor. The successor is the active route currently in use, while an active route refers to a route that is being actively calculated by the EIGRP process, and a passive route is one that is not actively updating or changing. Understanding these distinctions is crucial for managing EIGRP networks effectively.