CCNA Network Services and Security 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.

• ✗

  The OSPF /16 route, because dynamic routes override static routes learned later.

  Why it's wrong here

  Dynamic protocols do not override static routes in the forwarding decision; route preference is determined first by longest-prefix match, and then by administrative distance only when two routes have the same prefix length. Here, the OSPF /16 route is less specific than the static /24 route, so it loses the longest-match comparison regardless of how recently it was learned. Even if the OSPF route was received after the static route, it cannot displace a more specific static route.

  When this WOULD be correct

  In a scenario where the question states that OSPF routes are configured with a higher administrative distance than static routes, the OSPF /16 route could override the static route. For example, if the static route had an administrative distance of 200 and the OSPF route had an administrative distance of 110, the OSPF route would be used.

• ✓

  The static /24 route, because it is the longest-prefix match.

  Why this is correct

  The router performs a longest-prefix-match lookup in its forwarding table, and 10.55.0.0/24 has a longer prefix (more specific) than 10.55.0.0/16. Because the static route matches more bits of the destination address, it is the best route for any traffic destined to that subnet. This rule takes precedence over administrative distance or route source, so the /24 static route is always selected over the /16 OSPF route.

• ✗

  Both routes equally, because they point to the same major network.

  Why it's wrong here

  Both routes cannot be used equally because longest-prefix match dictates that only the /24 route is used for packets destined to 10.55.x.x within that subnet. Equal-cost load balancing only applies when multiple routes have the same prefix length and same metric; these routes have different lengths. The concept of a major network boundary does not cause equal-cost behavior, as routing decisions are always based on prefix length and not on classful addressing.

  When this WOULD be correct

  In a different scenario where both routes are configured with equal administrative distances and no specific prefix matching rules apply, a question might ask which route would be used if both were equally preferred. In such a case, the answer could be that both routes are considered equally valid for traffic to the same major network.

• ✗

  Neither route, because overlapping routes are invalid.

  Why it's wrong here

  Overlapping IPv4 routes are entirely normal and valid: a router can simultaneously hold a /16 and a /24 that cover the same address space. The presence of both routes does not create a conflict or invalidate either route; they simply coexist in the RIB. The forwarding process resolves the overlap by selecting the longest matching prefix, so both routes remain valid entries in the routing table.

  When this WOULD be correct

  In a different scenario, if the question stated that the routing table had a configuration that explicitly marked overlapping routes as invalid or if the router was configured to reject any overlapping static routes, then this option could be correct.

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?”

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