- A
Configuring an interface as passive stops OSPF from sending Hello packets out of that interface, but OSPF will still advertise the connected network in its LSAs.
Passive-interface suppresses OSPF Hello packets, preventing neighbor formation on that interface, yet the network is still advertised via the Router LSA.
- B
For two OSPF routers to establish full adjacency, they must agree on the Hello and Dead intervals.
Mismatched Hello or Dead timers will cause OSPF neighbors to remain in the EXSTART or DOWN state, preventing full adjacency.
- C
The network command with a wildcard mask of 0.0.0.0 will enable OSPF on the exact matching interface, but it will also prevent OSPF from forming adjacencies on that interface.
Why wrong: The network command simply enables OSPF on the interface; it has no effect on adjacency formation once the interface is active in OSPF.
- D
Using the passive-interface default command makes all OSPF interfaces passive, which means OSPF will not advertise any connected networks.
Why wrong: Even with passive-interface default, OSPF still includes the subnets of those interfaces in Type-1 LSAs; adjacency is blocked, but route advertisement continues.
- E
The network command with a wildcard mask of 0.0.0.255 area 0 will match any interface whose IP address falls within that /24 subnet, but OSPF will only attempt to form adjacencies on the interface with the highest IP address in that range.
Why wrong: OSPF attempts to form adjacencies on all active OSPF interfaces matched by the network command, not just the highest IP. The feature described resembles HSRP or DR/BDR election, not interface selection.
Quick Answer
The answer is that OSPF neighbor adjacency requires matching Hello and Dead intervals, while a passive interface prevents adjacency formation but still advertises the connected network. This is correct because OSPF routers must agree on these timers to exchange Hello packets and maintain neighbor relationships; if the intervals differ, the routers will not recognize each other as valid neighbors. On the CCNA 200-301 v2 exam, this concept tests your understanding of how OSPF discovers neighbors and how the passive-interface command modifies behavior without suppressing route advertisement. A common trap is assuming a passive interface stops all OSPF activity, but it only blocks Hello packets—the network is still included in Type 1 LSAs. Remember the mnemonic: “Passive blocks Hellos, not routes.”
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 are true about OSPFv2 neighbor adjacency, network statements, and passive interfaces?
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
Configuring an interface as passive stops OSPF from sending Hello packets out of that interface, but OSPF will still advertise the connected network in its LSAs.
Option A is correct because configuring an interface as passive in OSPFv2 prevents the router from sending Hello packets out of that interface, which stops neighbor discovery and adjacency formation. However, OSPF still includes the connected network of that passive interface in its Type 1 Router LSAs, allowing the network to be advertised to other OSPF routers.
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.
- ✓
Configuring an interface as passive stops OSPF from sending Hello packets out of that interface, but OSPF will still advertise the connected network in its LSAs.
- ✓
For two OSPF routers to establish full adjacency, they must agree on the Hello and Dead intervals.
Why this is correct
Mismatched Hello or Dead timers will cause OSPF neighbors to remain in the EXSTART or DOWN state, preventing full adjacency.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The network command with a wildcard mask of 0.0.0.0 will enable OSPF on the exact matching interface, but it will also prevent OSPF from forming adjacencies on that interface.
Why it's wrong here
The network command simply enables OSPF on the interface; it has no effect on adjacency formation once the interface is active in OSPF.
- ✗
Using the passive-interface default command makes all OSPF interfaces passive, which means OSPF will not advertise any connected networks.
Why it's wrong here
Even with passive-interface default, OSPF still includes the subnets of those interfaces in Type-1 LSAs; adjacency is blocked, but route advertisement continues.
- ✗
The network command with a wildcard mask of 0.0.0.255 area 0 will match any interface whose IP address falls within that /24 subnet, but OSPF will only attempt to form adjacencies on the interface with the highest IP address in that range.
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.
✓Configuring an interface as passive stops OSPF from sending Hello packets out of that interface, but OSPF will still advertise the connected network in its LSAs.Correct answer▾
Why this is correct
Passive-interface suppresses OSPF Hello packets, preventing neighbor formation on that interface, yet the network is still advertised via the Router LSA.
✗The network command with a wildcard mask of 0.0.0.0 will enable OSPF on the exact matching interface, but it will also prevent OSPF from forming adjacencies on that interface.Wrong answer — click to see why▾
Why this is wrong here
A wildcard mask of 0.0.0.0 only matches one exact IP address. It does not impose any restriction on adjacency.
✗Using the passive-interface default command makes all OSPF interfaces passive, which means OSPF will not advertise any connected networks.Wrong answer — click to see why▾
Why this is wrong here
Passive interfaces still advertise their networks—they just do not send or receive Hello packets. Only adjacency is suppressed.
✗The network command with a wildcard mask of 0.0.0.255 area 0 will match any interface whose IP address falls within that /24 subnet, but OSPF will only attempt to form adjacencies on the interface with the highest IP address in that range.Wrong answer — click to see why▾
Why this is wrong here
The network command matches multiple interfaces; OSPF then tries to form adjacencies on every enabled interface, regardless of IP address order.
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 misconception that a passive interface stops network advertisement, when in fact it only stops Hello packets and adjacency formation while still advertising the connected network in LSAs.
Trap categories for this question
Command / output trap
The network command simply enables OSPF on the interface; it has no effect on adjacency formation once the interface is active in OSPF.
Detailed technical explanation
How to think about this question
OSPFv2 uses Hello packets to discover neighbors and maintain adjacencies; the Hello and Dead intervals must match between neighbors for adjacency to form (as stated in Option B, which is correct). Passive interfaces are commonly used on loopback interfaces or LAN segments where no OSPF neighbor exists, allowing the network to be advertised without wasting resources on Hello packets. The network command under router ospf uses a wildcard mask to match interfaces, and OSPF will form adjacencies on all matched interfaces unless they are explicitly configured as passive.
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: Configuring an interface as passive stops OSPF from sending Hello packets out of that interface, but OSPF will still advertise the connected network in its LSAs. — Option A is correct because configuring an interface as passive in OSPFv2 prevents the router from sending Hello packets out of that interface, which stops neighbor discovery and adjacency formation. However, OSPF still includes the connected network of that passive interface in its Type 1 Router LSAs, allowing the network to be advertised to other OSPF routers.
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 →
Same concept, more angles
1 more ways this is tested on 200-301
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which two statements about OSPF neighbor requirements on a shared Ethernet segment are correct? (Choose two.)
medium- ✓ A.They must be in the same OSPF area on that link.
- ✓ B.They must use the same subnet on the connected interfaces.
- C.They must have identical router IDs.
- D.They must use the same process ID number on both routers.
Why A: Neighbors must agree on key parameters such as area ID and subnet, and they exchange Hello packets on the segment.
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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