What is defined as the Feasible Distance (FD) in EIGRP?

Feasible Distance (FD) in EIGRP is defined as the total cost to reach a destination. This cost is calculated based on various metrics, including bandwidth, delay, reliability, load, and MTU. When a router evaluates potential routes to a destination, it considers the Feasible Distance as a key metric for determining the best path. The FD is particularly important because it allows the router to make informed routing decisions by comparing the total cost of different routes to the same destination.

The other options do not accurately represent the concept of Feasible Distance. For instance, the metric to the nearest neighbor focuses only on the direct route to the next hop rather than the overall cost to reach the destination. Similarly, cumulative delay across all routers and the number of hops to a destination do not encompass the comprehensive calculations involved in determining the total cost, which includes various factors beyond just delay or hop count. Thus, defining Feasible Distance as the total cost incorporates all these considerations, providing a holistic view of the routing path's efficiency.