hardMultiple ChoiceObjective-mapped
300-410 Practice Question: Is troubleshooting an OSPFv2 adjacency issue…
A network engineer is troubleshooting an OSPFv2 adjacency issue between two routers across a Frame Relay network. R1 and R2 are connected via a point-to-point subinterface. The engineer configures 'ip ospf network point-to-point' on both subinterfaces. However, the adjacency does not form. 'show ip ospf interface' on R1 shows the interface is up and OSPF is enabled, but no neighbors are seen. What is the most likely cause?
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 Frame Relay map is missing or the DLCI is not assigned to the subinterface.
On Frame Relay point-to-point subinterfaces, the OSPF network type should be point-to-point, but the adjacency may still fail if the Layer 2 mapping is incorrect. The subinterface must be mapped to the correct DLCI. If the 'frame-relay interface-dlci' command is missing or misconfigured, the router cannot send packets to the neighbor, even though OSPF is enabled. The engineer should verify the DLCI mapping.
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 is set to broadcast, causing a DR/BDR election that fails on a point-to-point subinterface.
Why it's wrong here
The engineer set it to point-to-point, so this is not the issue.
- ✗
The subinterface is not configured with an IP address.
Why it's wrong here
If there were no IP address, OSPF would not be enabled on the interface.
- ✓
The Frame Relay map is missing or the DLCI is not assigned to the subinterface.
Why this is correct
Without a proper DLCI mapping, the router cannot send Layer 2 frames to the neighbor, preventing OSPF hello packets from being exchanged.
- ✗
The OSPF hello and dead timers are mismatched between R1 and R2.
Why it's wrong here
While timer mismatch can cause adjacency issues, it is less likely than a Layer 2 problem, and the stem does not indicate any timer configuration.
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.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 300-410 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 300-410 exam.