What is used to compare routes learned via the same routing protocol?

The correct choice focuses on the concept of metric, which is a value assigned to a specific route learned through a routing protocol to determine its desirability relative to other routes. Different routing protocols use different metrics, such as bandwidth, delay, load, and reliability, to compute the cost associated with a route.

Metrics play a crucial role when routers learn multiple routes to the same destination via the same protocol. When a router receives multiple routes, it will evaluate the metrics of those routes and select the one with the lowest metric as the best path. This ensures that the router forwards traffic using the most efficient route based on the parameters defined by the specific routing protocol in use.

While Administrative Distance (AD) is important for comparing routes learned through different routing protocols, it does not apply to routes sourced from the same protocol. Therefore, it is not a factor in comparing the desirability of routes within the same routing protocol. Similarly, Route Protocol Cost is a non-standard term and is often used interchangeably with metric, so it doesn’t demonstrate a widely accepted definition in routing protocol contexts. Interface Bandwidth, while relevant in determining the capacity of a link, does not serve as a comparative value for route selection beyond its role in contributing to metrics. Therefore,