- A
The administrative distance of the backup route is 10, so it is not installed while the primary route still exists.
Why wrong: When the primary interface fails, the primary route is removed from the table, allowing a floating route with a higher AD (10) to be installed, provided the floating route is valid.
- B
The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete.
A static route with a link-local next-hop requires an exit interface to be valid; omitting it causes the route to stay out of the routing table.
- C
The floating static route will be installed only if the primary link is administratively shut down, not after a physical failure.
Why wrong: Any failure (physical or administrative) that causes the primary route to be removed makes the floating static candidate, as long as the floating route itself is valid.
- D
The next-hop fe80::2 is unreachable because IPv6 neighbor discovery is disabled on the backup interface.
Why wrong: 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.
Quick Answer
The correct answer is that the floating static route fails because an IPv6 static route with a link-local next-hop requires an exit interface to be complete. A link-local address like fe80::2 is not globally unique; it exists on every IPv6-enabled interface, so the router cannot determine which interface to use for neighbor discovery without explicitly specifying the exit interface, such as GigabitEthernet0/1. On the CCNA 200-301 v2 exam, this concept tests your understanding of IPv6 static route syntax and the unique behavior of link-local addresses—a common trap is assuming a next-hop alone is sufficient, as it would be with a global unicast address. Remember that for IPv6, link-local next-hops are interface-specific, so the exit interface is mandatory to resolve the Layer 2 address. Memory tip: “Link-local needs a local link—always name the exit interface.”
CCNA IP Routing Practice Question
This 200-301 practice question tests your understanding of ip routing. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An enterprise network uses an IPv6 dual-stack design. Router R1 has a primary default route ::/0 via 2001:db8:1::1 with AD 1 and a floating default route with AD 10 via link-local address fe80::2. After the primary link fails, the floating route fails to install, and R1 loses all external connectivity. The administrator confirms the backup interface is up/up.
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"primary"Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete.
Option B is correct because a floating static route using a link-local next-hop (fe80::2) must also specify an exit interface (e.g., GigabitEthernet0/1) to be considered complete. Without the exit interface, the router cannot determine which interface to use for neighbor discovery, leaving the route incomplete and unable to be installed into the routing table. This is a common requirement for IPv6 static routes with link-local addresses, as the next-hop is not globally unique.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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
When the primary interface fails, the primary route is removed from the table, allowing a floating route with a higher AD (10) to be installed, provided the floating route is valid.
- ✓
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
A static route with a link-local next-hop requires an exit interface to be valid; omitting it causes the route to stay out of the routing table.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
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
Any failure (physical or administrative) that causes the primary route to be removed makes the floating static candidate, as long as the floating route itself is valid.
- ✗
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.
✓The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete.Correct answer▾
Why this is correct
A static route with a link-local next-hop requires an exit interface to be valid; omitting it causes the route to stay out of the routing table.
✗The administrative distance of the backup route is 10, so it is not installed while the primary route still exists.Wrong answer — click to see why▾
Why this is wrong here
A floating static route with a higher AD is installed when the lower AD route is removed because of interface failure.
✗The floating static route will be installed only if the primary link is administratively shut down, not after a physical failure.Wrong answer — click to see why▾
Why this is wrong here
Floating static routes do not distinguish between physical and administrative interface down events; the primary route is removed in both cases.
✗The next-hop fe80::2 is unreachable because IPv6 neighbor discovery is disabled on the backup interface.Wrong answer — click to see why▾
Why this is wrong here
The immediate cause is the missing exit interface; neighbor discovery configuration does not make an incomplete static route valid.
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?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the requirement that IPv6 static routes with link-local next-hops must include an exit interface, tricking candidates into thinking the route is valid without it or misattributing the failure to administrative distance or interface status.
Detailed technical explanation
How to think about this question
In IPv6, when a static route uses a link-local next-hop, the router must know the exit interface to perform neighbor discovery (ND) and resolve the next-hop MAC address. The command syntax is 'ipv6 route ::/0 fe80::2 GigabitEthernet0/1' — omitting the interface makes the route inactive. This behavior is defined in RFC 4861 and is a common misconfiguration in dual-stack networks where backup links rely on link-local addressing.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
What to study next
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FAQ
Questions learners often ask
What does this 200-301 question test?
IP Routing — This question tests IP Routing — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete. — Option B is correct because a floating static route using a link-local next-hop (fe80::2) must also specify an exit interface (e.g., GigabitEthernet0/1) to be considered complete. Without the exit interface, the router cannot determine which interface to use for neighbor discovery, leaving the route incomplete and unable to be installed into the routing table. This is a common requirement for IPv6 static routes with link-local addresses, as the next-hop is not globally unique.
What should I do if I get this 200-301 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jun 25, 2026
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.
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