What is used for EIGRP route metric calculations?

EIGRP (Enhanced Interior Gateway Routing Protocol) utilizes a composite metric for path selection, primarily based on bandwidth and delay. The correct choice highlights that the slowest link and the delay of all links are used for these calculations.

In EIGRP, the metric is derived from the bandwidth of the slowest link in the path to the destination and the cumulative delay from source to destination. This methodology ensures that the overall performance of a path is considered, especially in scenarios where there may be links with varying speeds and latencies. The employed formula for calculating the EIGRP metric is:

Metric = (K1 * bandwidth + K2 * bandwidth / (256 - load) + K3 * delay + K5 / (reliability + K4))

In this formula, the bandwidth of the slowest link and the total delay are crucial for determining the best route for packet forwarding. By considering the slowest link, EIGRP avoids potential bottlenecks that could arise from faster links that do not represent the entire path's performance.

This approach allows EIGRP to ensure that paths with potentially higher throughput are chosen in a way that still takes delay into account, leading to a more efficient routing decision.