Best Path Selection for Cisco Routers

Which attribute does a router use to select the best path when two or more different routes to the same destination exist from two different routing protocols?

Question

Which attribute does a router use to select the best path when two or more different routes to the same destination exist from two different routing protocols?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

C.

Administrative distance is the feature used by routers to select the best path when there are two or more different routes to the same destination from different routing protocols.

Administrative distance defines the reliability of a routing protocol.

When a router receives multiple routes to the same destination from different routing protocols, it needs to choose the best path to forward the traffic. The router determines the best path based on several factors, including the administrative distance and metric.

The administrative distance is a rating of the trustworthiness of the source of the routing information. It is a numerical value assigned to each routing protocol, which determines the preference of one protocol over another. For example, a router might trust a route received from a directly connected network more than a route received from an external source. The administrative distance is used to select the best path when multiple routing protocols provide routes to the same destination. The protocol with the lowest administrative distance is preferred.

The metric is a value used by a routing protocol to measure the desirability of a route. It is used to compare routes from the same routing protocol to the same destination. The metric can be based on several factors, including the hop count, bandwidth, delay, reliability, and load. For example, a routing protocol might use the hop count to determine the shortest path to a destination. The route with the lowest metric is preferred.

In summary, when a router receives multiple routes to the same destination from different routing protocols, it uses the administrative distance to select the best path between the routing protocols. Within a single routing protocol, the router uses the metric to select the best path. The protocol with the lowest administrative distance and the route with the lowest metric are preferred.