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.

• ✗

  The administrative distance of the backup route is 10, so it is not installed while the primary route still exists.

  Why it's wrong here

  The administrative distance (AD) of 10 on the floating static route makes it less preferred than the primary route while that primary is present, but this is the intended behavior of a floating static route. Once the primary route is removed from the routing table, the AD-10 route becomes eligible for installation, provided it is valid. The fact that the backup route still does not appear after the primary disappears points to a defect in the route itself—not the AD value. Therefore, the AD alone does not explain the missing route; the missing exit interface is the real cause.

• ✓

  The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete.

  Why this is correct

  An IPv6 static route that uses a link-local next-hop such as fe80::2 must also specify the exit interface because link-local addresses are only meaningful on a specific link. Without that interface keyword, the router cannot determine which interface to use to reach the next hop, so the route is considered incomplete and is not installed in the routing table. This remains true even if the next-hop address is otherwise reachable, and it is exactly why the backup route fails to appear when the primary route is removed. The correct configuration would include the outgoing interface, for example 'ipv6 route 2001:db8::/32 GigabitEthernet0/1 fe80::2'.

• ✗

  The floating static route will be installed only if the primary link is administratively shut down, not after a physical failure.

  Why it's wrong here

  This option incorrectly claims that the floating static route activates only after an administrative shutdown, not after a physical link failure. In reality, the router's decision to install a floating route is based solely on whether the primary route still exists in the routing table; any event that removes that primary route—whether a physical interface down, a protocol failure, or an administrative shutdown—makes the backup route a candidate. The router does not care how the primary route disappeared, only whether the backup route is valid and reachable. Since the backup route here is invalid because the exit interface is missing, it will not be installed regardless of the failure type.

• ✗

  The next-hop fe80::2 is unreachable because IPv6 neighbor discovery is disabled on the backup interface.

  Why it's wrong here

  While neighbor discovery must succeed for the next-hop to be reachable, the absence of an exit interface in the static route prevents the router from even attempting neighbor discovery, so the route is invalid regardless of ND state.

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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