Question 28 of 1,819
IP RoutingmediumMultiple SelectObjective-mapped

Quick Answer

The correct answer is that the passive-interface command in OSPF prevents the router from sending Hello packets on the specified interface. This occurs because the command suppresses all OSPF protocol traffic—including Hello, DD, LSR, LSU, and LSAck packets—on that interface, which stops the router from forming any neighbor adjacency. However, the network prefix of the passive interface is still included in the router’s Type-1 LSA and is advertised to the rest of the OSPF domain through active interfaces. On the CCNA 200-301 v2 exam, this concept tests your understanding of how OSPF separates control-plane neighbor discovery from data-plane route advertisement. A common trap is assuming that a passive interface hides the network entirely, but in fact the prefix is still reachable. A helpful memory tip: “Passive stops the chatter, but the route still matters.”

CCNA IP Routing Practice Question

This 200-301 practice question tests your understanding of ip routing. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.

Which TWO statements correctly describe the behavior of the passive-interface command in single-area OSPFv2?

Question 1mediummulti select
Review the full OSPF breakdown →

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

It prevents the router from sending Hello packets on the specified interface.

The passive-interface command in OSPFv2 suppresses all OSPF protocol packets (Hello, DD, LSR, LSU, LSAck) on the specified interface, preventing neighbor adjacency formation. However, the network prefix of that interface is still included in the router LSA and advertised through active interfaces to the OSPF domain. Option A is correct because Hello packets are suppressed. Option C is correct because the prefix is still advertised in LSAs. Option B is incorrect after rewording: it states that the network is not advertised, which is false. Option D is incorrect because passive-interface does not affect data traffic forwarding. Option E is incorrect because the network remains in the OSPF routing table.

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.

  • It prevents the router from sending Hello packets on the specified interface.

    Why this is correct

    Passive-interface in OSPF suppresses Hello packets, preventing OSPF neighbor discovery.

    Related concept

    Read the scenario before looking for a memorised answer.

  • It prevents the router from advertising the network in OSPF LSAs.

    Why it's wrong here

    This is false because the network under a passive interface is still included in the router LSA and advertised through active interfaces.

  • The network associated with the passive interface is still advertised in OSPF LSAs.

    Why this is correct

    Even with passive-interface, the network is included in OSPF Type 1 LSAs and advertised to OSPF neighbors.

    Related concept

    Read the scenario before looking for a memorised answer.

  • It disables the interface for any OSPF traffic, including data traffic.

    Why it's wrong here

    The passive-interface command only affects OSPF control plane traffic (Hello packets) on the interface. Data traffic is still forwarded normally through the interface, and the interface remains fully operational for all other protocols and forwarding.

  • It removes the network from the OSPF routing table.

    Why it's wrong here

    The passive-interface command does not remove the network from the OSPF routing table. The network is still advertised via LSAs and remains in the routing table as an OSPF route. The command only prevents the interface from forming OSPF adjacencies.

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.

It prevents the router from sending Hello packets on the specified interface.Correct answer

Why this is correct

Passive-interface in OSPF suppresses Hello packets, preventing OSPF neighbor discovery.

It prevents the router from advertising the network in OSPF LSAs.Wrong answer — click to see why

Why this is wrong here

This is false because the network under a passive interface is still included in the router LSA and advertised through active interfaces.

Why candidates choose this

Students often confuse OSPF with distance vector protocols like RIP, where the passive-interface command stops sending routing updates. In OSPF, the term 'routing updates' is misleading because OSPF uses LSAs, not periodic updates.

It disables the interface for any OSPF traffic, including data traffic.Wrong answer — click to see why

Why this is wrong here

The passive-interface command only affects OSPF control plane traffic (Hello packets) on the interface. Data traffic is still forwarded normally through the interface, and the interface remains fully operational for all other protocols and forwarding.

Why candidates choose this

The word 'passive' might imply that the interface is disabled or inactive for all traffic. However, in OSPF context, it only means the interface does not actively send Hello packets to discover neighbors.

It removes the network from the OSPF routing table.Wrong answer — click to see why

Why this is wrong here

The passive-interface command does not remove the network from the OSPF routing table. The network is still advertised via LSAs and remains in the routing table as an OSPF route. The command only prevents the interface from forming OSPF adjacencies.

Why candidates choose this

Some might think that if an interface is passive, its network should not be advertised. However, OSPF still includes the network in LSAs to ensure reachability, even if no neighbors are on that interface.

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

A common mistake is confusing passive-interface in OSPF with RIP or EIGRP; in OSPF, it suppresses all control packets on the interface, but the network is still advertised in LSAs via other interfaces.

Trap categories for this question

  • Command / output trap

    The passive-interface command only affects OSPF control plane traffic (Hello packets) on the interface. Data traffic is still forwarded normally through the interface, and the interface remains fully operational for all other protocols and forwarding.

Detailed technical explanation

How to think about this question

When an interface is configured as passive under OSPF, the router still includes the interface's network prefix in its router LSA (Type 1) and network LSA (Type 2) as a stub network, ensuring reachability is advertised to other OSPF routers. This is commonly used on loopback interfaces or interfaces connected to non-OSPF networks to prevent unnecessary neighbor discovery while still advertising the subnet.

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

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related practice questions

Related 200-301 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free 200-301 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

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: It prevents the router from sending Hello packets on the specified interface. — The passive-interface command in OSPFv2 suppresses all OSPF protocol packets (Hello, DD, LSR, LSU, LSAck) on the specified interface, preventing neighbor adjacency formation. However, the network prefix of that interface is still included in the router LSA and advertised through active interfaces to the OSPF domain. Option A is correct because Hello packets are suppressed. Option C is correct because the prefix is still advertised in LSAs. Option B is incorrect after rewording: it states that the network is not advertised, which is false. Option D is incorrect because passive-interface does not affect data traffic forwarding. Option E is incorrect because the network remains in the OSPF routing table.

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.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 11, 2026

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

Sign in to join the discussion.

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.