CCNA IP Routing Practice Question
Network Topology
You are connected to R1. R1 has OSPF configured on GigabitEthernet0/0 with network 10.0.0.0 0.0.0.3 area 1, ip ospf hello-interval 10, and ip ospf dead-interval 40. R2 has OSPF configured on its GigabitEthernet0/0 with network 10.0.0.0 0.0.0.3 area 0, ip ospf hello-interval 5, and ip ospf dead-interval 20. Correct these mismatches so that R1 and R2 become OSPF neighbors.
⚠ Common exam trap
The exam trap is that candidates may focus on only one mismatch (area or timers) and forget that both must match. Additionally, they might assume that the router they are connected to should not be changed, or that default timers are always correct. Always verify all OSPF parameters that must match: area ID, hello/dead intervals, network type, and authentication.
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
✓
On R1, change the network statement to area 0 and set ip ospf hello-interval 5 and ip ospf dead-interval 20 under the interface.
The OSPF adjacency fails due to two mismatches. First, the area is mismatched: R1 uses area 1, R2 uses area 0 (both must be the same area, typically area 0). Second, the hello and dead timers are mismatched: R1 uses Hello 10/Dead 40, R2 uses Hello 5/Dead 20. To fix, on R1 change the network statement to area 0 and adjust timers to match R2 (or vice versa). The solution below changes R1's area to 0 and sets hello to 5 and dead to 20 to match R2.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
On R1, change the network statement to area 0 and set ip ospf hello-interval 5 and ip ospf dead-interval 20 under the interface.
Why this is correct
This corrects both mismatches: area is changed to 0 to match R2, and timers are set to hello 5/dead 20 to match R2's timers. OSPF requires identical area IDs and hello/dead intervals on a link for adjacency to form.
- ✗
On R2, change the network statement to area 1 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.
Why it's wrong here
This is incorrect because while it aligns the area and timers, it changes R2's configuration to match R1's original settings. However, the question asks to correct the issues, and changing R1 is the more straightforward approach as R1 is the router you are connected to. Also, area 1 is not the standard backbone area; area 0 is typically used for single-area OSPF.
- ✗
On R1, change the network statement to area 0 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.
Why it's wrong here
This is incorrect because while it fixes the area mismatch by setting area 0, it does not fix the timer mismatch. R1's timers remain at hello 10/dead 40, which do not match R2's hello 5/dead 20. OSPF requires timers to match for adjacency.
- ✗
On R2, change the network statement to area 0 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.
Why it's wrong here
This is incorrect because it changes R2's area to 0 (which is already correct) but changes R2's timers to hello 10/dead 40, which would then mismatch with R1's timers. The area is already correct on R2, so no change is needed there. The timer change would create a new mismatch.
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.
✓On R1, change the network statement to area 0 and set ip ospf hello-interval 5 and ip ospf dead-interval 20 under the interface.Correct answer▾
Why this is correct
This corrects both mismatches: area is changed to 0 to match R2, and timers are set to hello 5/dead 20 to match R2's timers. OSPF requires identical area IDs and hello/dead intervals on a link for adjacency to form.
✗On R2, change the network statement to area 1 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the question implies you are connected to R1, so configuring R1 is the expected action. Additionally, using area 1 instead of area 0 is not recommended for a single-area design.
Why candidates choose this
Candidates might think that changing either router is acceptable, but the question context ("You are connected to R1") suggests R1 should be modified. Also, some may not realize that area 0 is the preferred area for single-area OSPF.
✗On R1, change the network statement to area 0 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the timers are not changed to match R2; they remain at the original values.
Why candidates choose this
Candidates might think that only the area needs to be corrected, overlooking the timer mismatch. They may also assume that the default timers (hello 10/dead 40) are standard and should be used.
✗On R2, change the network statement to area 0 and set ip ospf hello-interval 10 and ip ospf dead-interval 40 under the interface.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that R2's area is already 0, so changing it to area 0 is redundant. Changing R2's timers to match R1's original timers would still leave a mismatch because R1's timers are not changed.
Why candidates choose this
Candidates might think that both routers need to be modified, or that changing the router you are not connected to is acceptable. They may also incorrectly assume that the default timers (hello 10/dead 40) are the correct ones to use.
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?”
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
Go deeper
Related to this question
Learn chapter
OSPFv3 Single-Area Configuration for IPv6
Key term
Area 0
Area 0 is the backbone area in OSPF routing that connects all other OSPF areas to ensure a loop-free and efficient network routing topology.
Key term
OSPF
OSPF is a link-state routing protocol used to find the best path for data packets to travel across IP networks, like a smart GPS that recalculates routes when traffic changes.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.