hardMultiple Choice
300-410 Practice Question: Runs the following command to verify OSPF SPF…
A network engineer runs the following command to verify OSPF SPF calculations:
R1# show ip ospf statistics
OSPF Router with ID (1.1.1.1) (Process ID 1)
Area 0: SPF algorithm executed 12 times
SPF calculation time (in msec): Total: 12, Average: 1.0 Minimum: 0, Maximum: 2 Last SPF due to: LSA change Number of LSA changes: 5 Number of LSA deletions: 2 Number of LSA additions: 3 Number of LSA updates: 0
Area 1: SPF algorithm executed 3 times
SPF calculation time (in msec): Total: 3, Average: 1.0 Minimum: 0, Maximum: 1 Last SPF due to: LSA change Number of LSA changes: 2 Number of LSA deletions: 0 Number of LSA additions: 2 Number of LSA updates: 0
What does this output indicate?
⚠ Common exam trap
The trap is reading 'SPF calculation time' and assuming any nonzero value indicates a performance problem, when in fact the exam wants you to compare relative SPF run counts and LSA change counts between areas to infer topology churn.
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
✓
Area 0 has experienced more network changes than Area 1, as indicated by higher SPF runs and LSA changes.
The output shows Area 0 executed the SPF algorithm 12 times with 5 LSA changes (2 deletions, 3 additions), while Area 1 executed SPF only 3 times with 2 LSA changes. More SPF runs and more LSA changes in Area 0 directly indicate greater topology churn in that area. The 'Last SPF due to: LSA change' line confirms the trigger was an LSA event, not a timer.
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 has not performed any SPF calculations.
Why it's wrong here
The output explicitly reports the SPF algorithm executed 12 times in Area 0 and 3 times in Area 1, with per-area timing totals, contradicting any claim of zero calculations. It would be correct only if the counters showed zero executions and no recorded LSA changes.
- ✓
Area 0 has experienced more network changes than Area 1, as indicated by higher SPF runs and LSA changes.
Why this is correct
Area 0 shows 12 SPF executions against Area 1's 3, with five LSA changes versus two. Higher SPF runs and LSA counts directly evidence more frequent topology changes in Area 0, satisfying the comparison the stem asks about.
- ✗
The SPF calculation time is too high, indicating a performance issue.
Why it's wrong here
Maximum SPF times of 2 ms and 1 ms with averages of 1.0 ms are negligible, so no performance problem exists. It would be correct if the maximum values were large, indicating slow SPF runs caused by a large link-state database or unstable topology.
- ✗
The last SPF was triggered by a timer expiry.
Why it's wrong here
The output states the last SPF was due to an LSA change, not a timer expiry; OSPF SPF runs on topology changes, while the LSA refresh timer is 30 minutes. It would be correct if the trigger line read timer rather than LSA change.
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.