hardMultiple Choice
300-410 Practice Question: An engineer is troubleshooting a network where R1…
An engineer is troubleshooting a network where R1 and R2 are running EIGRP, and R2 redistributes a static route for 192.168.1.0/24 into EIGRP. R1 also learns the same prefix via OSPF from R3 with an AD of 110. The engineer observes that R1 prefers the EIGRP external route (AD 170) over the OSPF route. What configuration change would cause this behavior?
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 engineer applied the distance eigrp 90 100 command under EIGRP, lowering the AD for external routes to 100.
By default, EIGRP external routes have an AD of 170, and OSPF has AD 110, so OSPF should be preferred. If the EIGRP external route is preferred, the AD must have been lowered, likely via the distance command under EIGRP.
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 route is a type 5 LSA, which has a higher AD than type 3 LSAs.
Why it's wrong here
LSA type does not set administrative distance; OSPF's AD of 110 applies to all OSPF-learned routes regardless of LSA type. Type 5 LSAs carry external prefixes, but that does not raise their AD above EIGRP external's 170. LSA types describe flooding scope and origin, not preference.
- ✓
The engineer applied the distance eigrp 90 100 command under EIGRP, lowering the AD for external routes to 100.
Why this is correct
Lowering the external EIGRP administrative distance to 100 via the distance eigrp 90 100 command makes the redistributed static route (AD 100) beat the OSPF route (AD 110), explaining R1's preference for the EIGRP external path.
- ✗
The OSPF route has a metric of 20, while the EIGRP route has a metric of 2560.
Why it's wrong here
Metrics are only compared between routes of the same protocol; EIGRP's 2560 and OSPF's 20 are never weighed against each other. Administrative distance decides first, and 170 exceeds 110. Metric tuning is the correct approach when selecting between two EIGRP paths, not across protocols.
- ✗
The static route was redistributed with a route-map that sets the EIGRP metric to 1.
Why it's wrong here
Setting the EIGRP metric to 1 does not alter administrative distance, so the external EIGRP route still carries AD 170 and loses to OSPF's 110. Route-map metric manipulation is used to influence EIGRP path selection among EIGRP routes, not to override a competing protocol's AD.
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.
Go deeper
Related to this question
About these practice questions
This 300-410 question is part of Courseiva's 1,401-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
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.