In the context of distance-vector routing, what does administrative distance represent?

• A. The actual path length to a destination measured in hops.
• B. The perceived trustworthiness of a route learned from a particular routing protocol, influencing route selection.
• C. The total number of routes known by the router.
• D. A timer value used to invalidate routes after a failure.

Answer: (B)

Administrative distance is the trust level assigned to a route’s source protocol. In distance-vector routing, a router may learn the same destination from different protocols, and it uses this trust value to decide which route to use. The rule is simple: the route from the protocol with the lower administrative distance is preferred and installed in the routing table, even if another route has a better metric. This priority system lets you control route selection based on how trustworthy you consider each protocol’s information to be, which helps overall network stability and policy.

Other choices describe different concepts: actual path length in hops is a metric, not administrative distance; the total number of routes known is not about trust; and a timer value used to invalidate routes is route aging, not administrative distance.