hardMultiple Choice
300-410 Practice Question: An engineer configures OSPF area range on an ABR…
An engineer configures OSPF area range on an ABR to summarize routes. After configuration, some routes are still being advertised as individual LSAs into the backbone. Which is the most likely explanation?
⚠ Common exam trap
300-410 often tests the distinction between 'area range' (intra-area Type 1/2 summarization at ABR) and 'summary-address' (external Type 5/7 summarization at ASBR), catching candidates who assume area range summarizes everything.
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 area range command does not summarize external routes redistributed into OSPF.
The OSPF 'area range' command only summarizes intra-area (Type 1 and Type 2) LSAs at an ABR; it does not affect external routes redistributed into OSPF as Type 5 (or Type 7) LSAs. External routes must be summarized with the 'summary-address' command on the ASBR (or NSSA ABR for Type 7). That is why some routes continue to be advertised individually after area range is configured.
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 area range command does not summarize external routes redistributed into OSPF.
Why this is correct
Area range summarises only intra-area routes (type 3 LSAs) between areas. External routes redistributed into OSPF remain type 5 LSAs flooded domain-wide, so they continue appearing individually in the backbone. The stem's leftover individual LSAs are therefore external prefixes, which require the separate ASBR summary-range mechanism instead.
- ✗
The ABR is not configured with the summary-address command.
Why it's wrong here
OSPF area range summarises routes between areas on an ABR; summary-address is for external routes redistributed into OSPF, so its absence does not affect inter-area LSAs. It is tempting because both commands create summaries, but summary-address applies to redistributed external prefixes, not area range.
- ✗
The area range is configured on the wrong ABR.
Why it's wrong here
Configuring area range on the wrong ABR would leave the summarised LSAs absent entirely, not individual LSAs still advertised alongside them. Wrong-ABR placement is tempting when summarisation appears ineffective, but it is correct only when no ABR in the area has the range configured.
- ✗
The OSPF process needs to be cleared to apply the area range.
Why it's wrong here
Area range summarisation applies immediately to the OSPF link-state database; clearing the process only forces reconvergence and re-advertises the same individual LSAs. Clearing is tempting when stale or stuck adjacencies cause routing oddities, but here the summarisation itself is misconfigured, not the process state.
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.