hardMultiple Choice
300-410 Practice Question: Runs the following command on Router R3: R3# show…
A network engineer runs the following command on Router R3:
R3# show logging | include %OSPF-5-ADJCHG *Mar 1 00:05:10.123: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done *Mar 1 00:06:20.456: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired *Mar 1 00:07:30.789: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from DOWN to INIT, Received Hello *Mar 1 00:08:40.012: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from INIT to EXSTART, Event: start *Mar 1 00:09:50.345: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from EXSTART to EXCHANGE, Event: Negotiation Done *Mar 1 00:10:00.678: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from EXCHANGE to LOADING, Event: Exchange Done *Mar 1 00:11:10.901: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done *Mar 1 00:12:20.234: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
Based on this output, what is the most likely problem?
⚠ Common exam trap
300-410 often tests whether candidates can distinguish configuration mismatches (which block adjacency formation) from physical/link issues (which cause established adjacencies to flap), so candidates who see 'OSPF' and jump to area ID mismatch miss that the neighbor already reached FULL.
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
✓
There is a Layer 1 or Layer 2 issue causing intermittent connectivity on GigabitEthernet0/0.
The log shows the OSPF neighbor repeatedly reaching FULL and then dropping with 'Dead timer expired,' which means the router stopped receiving Hello packets from the neighbor within the dead interval (default 40 seconds, 4× the 10-second Hello). This pattern — adjacency forms, then dies, then re-forms — is characteristic of intermittent Layer 1 or Layer 2 connectivity (flapping link, bad cable, duplex mismatch, or a flaky switch port) rather than a configuration mismatch. A config mismatch would prevent the adjacency from reaching FULL in the first place.
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 process is misconfigured with mismatched area IDs.
Why it's wrong here
If area IDs mismatched, the neighbor would not reach FULL at all; the adjacency goes through all states, indicating correct area configuration.
- ✓
There is a Layer 1 or Layer 2 issue causing intermittent connectivity on GigabitEthernet0/0.
Why this is correct
The dead timer expiration indicates that hello packets are not received in time, which is often due to flapping interfaces or high error rates.
- ✗
The OSPF dead timer is set too high, causing slow convergence.
Why it's wrong here
A high dead timer would make the neighbor take longer to go down, but the pattern shows quick transitions, suggesting a short timer or actual connectivity loss.
- ✗
The router is running out of memory, causing OSPF process restarts.
Why it's wrong here
There is no indication of memory issues; the OSPF process is running and forming adjacencies repeatedly.
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 and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
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.