CCNA IP Routing Practice Question
Exhibit
R1# show ip ospf interface GigabitEthernet0/0
GigabitEthernet0/0 is up, line protocol is up
Internet Address 192.168.1.1/24, Area 0
Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State PASSIVE, 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
No Hellos (Passive interface)
Adjacent neighbor count is 0Refer to the exhibit. A network administrator is troubleshooting an OSPF adjacency on R1's GigabitEthernet0/0 interface connected directly to R2. R2 is powered on and shows correct OSPF configuration, but the adjacency is stuck in the INIT or DOWN state. Based on the output, what is the most likely cause of the failure?
⚠ Common exam trap
Cisco often tests the passive-interface command as a subtle cause of OSPF adjacency failure, where candidates mistakenly think it only affects routing updates (like in EIGRP) rather than Hello suppression in OSPF.
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 OSPF passive-interface command has been applied to GigabitEthernet0/0, preventing hello packets from being sent.
The adjacency is stuck in INIT or DOWN state, which indicates that R1 is not receiving OSPF Hello packets from R2. The passive-interface command on GigabitEthernet0/0 prevents R1 from sending Hellos, so R2 never sees R1, and R1 may see R2's Hellos (stuck in INIT) or not (stuck in DOWN). This matches the symptom exactly, as passive-interface suppresses outgoing Hellos while still allowing the interface to be advertised.
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 OSPF network type on R1's GigabitEthernet0/0 does not match the network type on R2.
Why it's wrong here
The output explicitly lists Network Type BROADCAST, which is the default for Ethernet interfaces, so there is no indication that R1's GigabitEthernet0/0 is configured with a different OSPF network type than R2. Even if a network type mismatch existed, OSPF uses Hello packets to negotiate and detect such mismatches; however, the interface is passive, meaning no Hellos are sent at all. Therefore, the absence of adjacency is not explained by network type mismatch—it is fully explained by the passive-interface configuration that suppresses all Hello transmission.
- ✗
The OSPF hello and dead timers on R1 do not match those configured on R2.
Why it's wrong here
The timers shown (Hello 10, Dead 40) are the default values and would match R2 if it also uses defaults. More importantly, the passive state means no hellos are transmitted, so timer mismatch is not the cause.
- ✗
The GigabitEthernet0/0 interface on R1 has been assigned to a different OSPF area than R2's connected interface.
Why it's wrong here
The output shows Area 0 for R1's interface. There is no indication of an area mismatch; R2 could also be in Area 0. The passive state prevents any hello exchange necessary to detect an area mismatch.
- ✓
The OSPF passive-interface command has been applied to GigabitEthernet0/0, preventing hello packets from being sent.
Why this is correct
The line 'No Hellos (Passive interface)' in the output is the direct and definitive indication that the GigabitEthernet0/0 interface has been configured with the OSPF passive-interface command. This command prevents OSPF from sending Hello packets out of this interface, and without Hellos, R1 cannot discover R2 or form an adjacency with it. Passive-interface is a common administrative choice to stop OSPF on a LAN segment while still advertising the connected subnet, but it breaks neighbor formation entirely, which is exactly the problem described in the scenario.
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 OSPF passive-interface command has been applied to GigabitEthernet0/0, preventing hello packets from being sent.Correct answer▾
Why this is correct
The line 'No Hellos (Passive interface)' in the output is the direct and definitive indication that the GigabitEthernet0/0 interface has been configured with the OSPF passive-interface command. This command prevents OSPF from sending Hello packets out of this interface, and without Hellos, R1 cannot discover R2 or form an adjacency with it. Passive-interface is a common administrative choice to stop OSPF on a LAN segment while still advertising the connected subnet, but it breaks neighbor formation entirely, which is exactly the problem described in the scenario.
✗The OSPF network type on R1's GigabitEthernet0/0 does not match the network type on R2.Wrong answer — click to see why▾
Why this is wrong here
Candidates may think network type mismatch when they see no adjacency, but the exhibit does not indicate a mismatch and explicitly shows the passive state.
✗The OSPF hello and dead timers on R1 do not match those configured on R2.Wrong answer — click to see why▾
Why this is wrong here
Timer mismatch is a classic troubleshooting trap, but the 'No Hellos (Passive interface)' message overrides any timer considerations.
✗The GigabitEthernet0/0 interface on R1 has been assigned to a different OSPF area than R2's connected interface.Wrong answer — click to see why▾
Why this is wrong here
Candidates may guess area mismatch as a cause, but the exhibit provides no evidence of it, while the passive-interface message is a direct cause.
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
OSPF
OSPF is a link-state routing protocol that uses the SPF algorithm to compute the shortest path to each destination within a single autonomous system.
Key term
Interface
An interface is a point of connection or interaction between two systems, devices, or software components that allows them to exchange information or signals.
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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.