mediumMultiple Choice
300-410 Practice Question: Runs the following command to troubleshoot a…
A network engineer runs the following command to troubleshoot a Network Logging and Syslog issue:
R1# debug ip ospf adj
Output: OSPF: 2 Way Communication to 10.0.0.2 on GigabitEthernet0/0, state 2WAY OSPF: Send hello to 224.0.0.5 on GigabitEthernet0/0 OSPF: Rcv DBD from 10.0.0.2 on GigabitEthernet0/0 seq 0x1E opt 0x52 flag 0x7 len 32 OSPF: NBR negotiation done. We are the SLAVE OSPF: Exchange done with 10.0.0.2 on GigabitEthernet0/0 OSPF: Build router LSA for area 0, router ID 10.0.0.1
What does this output indicate?
⚠ Common exam trap
The trap here is that candidates see 'SLAVE' and assume something is wrong, or see '2WAY' and think the adjacency failed — but 2-WAY is a normal intermediate state and SLAVE is a normal DBD negotiation role, not an error condition.
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 router is successfully forming an OSPF adjacency with neighbor 10.0.0.2.
The debug output shows the full OSPF adjacency progression: 2-Way state, DBD exchange with master/slave negotiation ('We are the SLAVE'), 'Exchange done', and router LSA generation. These messages confirm the neighbor relationship advanced past EXSTART/EXCHANGE into LOADING/FULL, indicating a successful adjacency formation. No authentication errors or MTU-related stalls appear in the output.
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 router is successfully forming an OSPF adjacency with neighbor 10.0.0.2.
Why this is correct
The debug shows the neighbour reaching 2WAY, completing database descriptor negotiation as SLAVE, and finishing the Exchange state. Building the router LSA for area 0 confirms the adjacency progressed to Full, so OSPF is successfully forming with 10.0.0.2 on GigabitEthernet0/0.
- ✗
The router is experiencing an OSPF authentication failure.
Why it's wrong here
Authentication failure prevents the neighbour reaching 2WAY and produces 'OSPF: Invalid authentication' or 'Rcv pkt from ... authentication' messages; here hellos and DBDs were accepted, proving authentication succeeded. Authentication keys matter when adjacencies fail before two-way state.
- ✗
The router is stuck in the EXSTART state due to MTU mismatch.
Why it's wrong here
The log shows EXSTART completed and EXCHANGE done, so adjacency progressed past DBD negotiation; an MTU mismatch stalls DBD exchange in EXSTART, producing mismatched sequence numbers and no 'Exchange done'. MTU tuning applies when neighbours repeatedly reset at EXSTART.
- ✗
The router is flooding LSAs to all neighbors.
Why it's wrong here
Flooding LSAs follows FULL adjacency and database synchronisation; the log ends at building the router LSA, before any neighbour reaches FULL. Flooding behaviour is the relevant check once adjacencies are established and link-state databases are synchronised.
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.