Which Parameter Determines the Best Path for EIGRP Routing?

C.

If a router learns two different paths for the same network from the same routing protocol, it has to decide which route is better and will be placed in the routing table.

Metric is the measure used to decide which route is better (lower number is better)

Each routing protocol uses its own metric.

For example, RIP uses hop counts as a metric, while OSPF uses cost.

https://study-ccna.com/administrative-distance-metric/

When a router running the Enhanced Interior Gateway Routing Protocol (EIGRP) receives multiple paths to the same destination, it selects the best path based on the metric value. The metric value in EIGRP is calculated based on several factors such as bandwidth, delay, reliability, load, and MTU.

The router calculates a composite metric for each path based on the sum of the values of these factors. EIGRP uses a default composite metric that is calculated as follows:

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

Where K1 to K5 are constants and their values can be changed to influence the metric calculation. The default values for these constants are:

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K1 = 1, K2 = 0, K3 = 1, K4 = 0, K5 = 1 

The router selects the path with the lowest metric value as the best path to the destination. Therefore, the answer to the question is C. metric.

Administrative distance is a parameter used by a router to select the best path when multiple routing protocols are used. It is a numerical value assigned to each routing protocol, indicating its trustworthiness. When a router receives multiple paths to the same destination from different routing protocols, it selects the path with the lowest administrative distance. Therefore, it is not used in this scenario.

Cost is a parameter used by other routing protocols such as OSPF to calculate the metric value. It is similar to the metric in EIGRP but is based only on the bandwidth of the link. Therefore, it is not used in this scenario.

As-path is a parameter used in Border Gateway Protocol (BGP) to prevent loops in the network. It is a list of autonomous system numbers that a packet must pass through to reach the destination. Therefore, it is not used in this scenario.