This 200-301 practice question tests your understanding of ip routing. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
Network Topology
You are connected to R1. Configure OSPFv2 on R1 and R2 so that they form a full adjacency and can exchange routes. The current configuration has mismatched hello/dead timers blocking the adjacency. Adjust only the necessary settings on R1 to match R2's OSPF timers.
R1# show running-config | section router ospf
router ospf 1
router-id 1.1.1.1
network 192.0.2.0 0.0.0.3 area 0
!
R1# show ip ospf interface gigabitethernet0/0
GigabitEthernet0/0 is up, line protocol is up
Internet Address 192.0.2.1/30, Area 0
Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State WAITING, Priority 1
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:01
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
R2# show running-config | section router ospf
router ospf 1
router-id 2.2.2.2
network 192.0.2.0 0.0.0.3 area 0
!
R2# show ip ospf interface gigabitethernet0/0
GigabitEthernet0/0 is up, line protocol is up
Internet Address 192.0.2.2/30, Area 0
Process ID 1, Router ID 2.2.2.2, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State WAITING, Priority 1
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5
oob-resync timeout 20
Hello due in 00:00:03
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
A
Configure 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface.
This is correct because OSPF requires matching hello and dead timers on both routers for adjacency formation. R2 uses hello 5 and dead 20, so R1 must be configured with the same values on the connecting interface.
B
Configure 'ip ospf hello-interval 10' and 'ip ospf dead-interval 40' on R2's interface to match R1's default timers.
Why wrong: This is incorrect because the question explicitly states to adjust only R1 to match R2's timers. Changing R2 would violate the constraint, and the default timers on R1 are already 10 and 40.
C
Configure 'ip ospf hello-interval 5' on R1's GigabitEthernet0/0 interface only; the dead interval will adjust automatically.
Why wrong: This is incorrect because OSPF does not automatically adjust the dead interval when the hello interval is changed. The dead interval must be explicitly configured to match; otherwise, it remains at the default (40) or previous value.
D
Configure 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface only; the hello interval will adjust automatically.
Why wrong: This is incorrect because OSPF does not automatically adjust the hello interval when the dead interval is changed. The hello interval must be explicitly configured to match; otherwise, it remains at the default (10).
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface.
The adjacency between R1 and R2 is not forming because the OSPF hello and dead timers are mismatched. R1 has default timers (Hello 10, Dead 40) while R2 has custom timers (Hello 5, Dead 20). To form an adjacency, OSPF timers must match on both ends. On R1, you need to configure the OSPF interface timers to match R2 by issuing 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on interface GigabitEthernet0/0. After applying these commands, the adjacency should come up.
Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Configure 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface.
Why this is correct
This is correct because OSPF requires matching hello and dead timers on both routers for adjacency formation. R2 uses hello 5 and dead 20, so R1 must be configured with the same values on the connecting interface.
Configure 'ip ospf hello-interval 10' and 'ip ospf dead-interval 40' on R2's interface to match R1's default timers.
Why it's wrong here
This is incorrect because the question explicitly states to adjust only R1 to match R2's timers. Changing R2 would violate the constraint, and the default timers on R1 are already 10 and 40.
✗
Configure 'ip ospf hello-interval 5' on R1's GigabitEthernet0/0 interface only; the dead interval will adjust automatically.
Why it's wrong here
This is incorrect because OSPF does not automatically adjust the dead interval when the hello interval is changed. The dead interval must be explicitly configured to match; otherwise, it remains at the default (40) or previous value.
✗
Configure 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface only; the hello interval will adjust automatically.
Why it's wrong here
This is incorrect because OSPF does not automatically adjust the hello interval when the dead interval is changed. The hello interval must be explicitly configured to match; otherwise, it remains at the default (10).
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.
✓Configure 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface.Correct answer▾
Why this is correct
This is correct because OSPF requires matching hello and dead timers on both routers for adjacency formation. R2 uses hello 5 and dead 20, so R1 must be configured with the same values on the connecting interface.
✗Configure 'ip ospf hello-interval 10' and 'ip ospf dead-interval 40' on R2's interface to match R1's default timers.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the instruction limits changes to R1 only; modifying R2 is not allowed.
Why candidates choose this
Candidates might think it's acceptable to change either router, but the question restricts adjustments to R1.
✗Configure 'ip ospf hello-interval 5' on R1's GigabitEthernet0/0 interface only; the dead interval will adjust automatically.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the dead interval is not automatically derived from the hello interval; it must be set separately.
Why candidates choose this
Candidates may recall that the dead interval is typically four times the hello interval and assume it adjusts automatically, but Cisco IOS requires explicit configuration.
✗Configure 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface only; the hello interval will adjust automatically.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the hello interval is not automatically derived from the dead interval; both must be set explicitly.
Why candidates choose this
Candidates may assume that setting the dead interval alone will cause the hello interval to adjust proportionally, but this is not the case in Cisco IOS.
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: OSPF can fail even when IP connectivity looks correct
OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.
Detailed technical explanation
How to think about this question
OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.
KKey Concepts to Remember
OSPF neighbours must agree on key parameters.
Router ID selection can affect neighbour relationships and LSDB output.
OSPF cost influences the preferred path.
A route can appear in OSPF information but not become the installed route.
TExam Day Tips
→Check area mismatch first when OSPF adjacency fails.
→Review passive interfaces when a network is advertised but no neighbour forms.
→Use show ip ospf neighbor and show ip route clues carefully.
Key takeaway
OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 200-301 question in full detail.
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 200-301 OSPF questions on adjacency and route selection.
IP Routing — This question tests IP Routing — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: Configure 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on R1's GigabitEthernet0/0 interface. — The adjacency between R1 and R2 is not forming because the OSPF hello and dead timers are mismatched. R1 has default timers (Hello 10, Dead 40) while R2 has custom timers (Hello 5, Dead 20). To form an adjacency, OSPF timers must match on both ends. On R1, you need to configure the OSPF interface timers to match R2 by issuing 'ip ospf hello-interval 5' and 'ip ospf dead-interval 20' on interface GigabitEthernet0/0. After applying these commands, the adjacency should come up.
What should I do if I get this 200-301 question wrong?
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 200-301 OSPF questions on adjacency and route selection.
What is the key concept behind this question?
OSPF neighbours must agree on key parameters.
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 →
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.
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.
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.
Sign in to join the discussion.