CCNA IP Routing Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  A route with a longer prefix length is always preferred over a route with a shorter prefix length, regardless of administrative distance.

  Why this is correct

  The longest-prefix match rule is the first criterion in the routing table lookup: a route with a longer subnet mask (e.g., /32) is always selected over a less specific route (e.g., /24) for the same destination, even if that less specific route has a much lower administrative distance. Administrative distance becomes relevant only after the router identifies the set of routes with the longest matching prefix length. For example, a static route to 10.0.0.0/24 with AD 1 will lose to an OSPF route to 10.0.0.0/32 with AD 110, because specificity determines the winning route before AD is ever considered.

• ✓

  A directly connected route has an administrative distance of 0 and is always preferred over any dynamic route for the same network.

  Why this is correct

  A directly connected route is automatically installed when an interface is configured with an IP address and is up; its administrative distance is 0, the lowest possible value. Because no other source can have an AD lower than 0, any directly connected route will beat a dynamic route (OSPF AD 110, EIGRP AD 90) for the same network, assuming the prefix lengths are the same. This is why directly connected networks are always preferred for forwarding and also why they are commonly used as the trust anchor in route redistribution.

• ✗

  If two routes have the same prefix length, the route with the higher administrative distance is preferred.

  Why it's wrong here

  This statement is the literal opposite of the correct behavior: when two routes share the same prefix length, the router uses administrative distance as a tie-breaker, and the lower AD value is preferred. A higher administrative distance indicates a less trustworthy route, so it will never win against a lower-AD route if both are in the routing table. For instance, an OSPF route with AD 110 beats a RIP route with AD 120 for the same /24 network because 110 is lower.

• ✗

  The metric is used to compare routes from different routing protocols.

  Why it's wrong here

  Metrics are only comparable within a single routing protocol; each protocol uses its own metric (OSPF cost, EIGRP composite, RIP hop count) and these values are not interchangeable. When a router receives routes to the same destination from different protocols, it first compares administrative distance, not metric, because AD is designed to express the trustworthiness of the route's source. After a single protocol is chosen, the metric then selects the best route from that protocol's candidates. Therefore, saying the metric is used to compare routes from different routing protocols confuses the two distinct selection phases.

• ✗

  A static route configured with an administrative distance of 200 will be preferred over an OSPF route with AD 110 for the same network.

  Why it's wrong here

  A static route with a configured administrative distance of 200 is a floating static route; it is not installed as long as any usable route with a lower AD exists. OSPF's default AD of 110 is lower than 200, so the OSPF route is preferred for the same network and the static route remains in the backup state. This technique is useful for providing a backup path, but in this scenario the OSPF route wins the comparison because a router always selects the route with the lower administrative distance when prefix lengths match.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”