hardMultiple ChoiceObjective-mapped
300-410 Practice Question: After redistributing OSPF into EIGRP, an EIGRP…
After redistributing OSPF into EIGRP, an EIGRP router becomes stuck-in-active (SIA) for certain routes. Router R1 config:
router eigrp 100
redistribute ospf 1 metric 10000 100 255 1 1500 !
router ospf 1
redistribute eigrp 100 subnets
R1# show ip eigrp topology 10.0.0.0/8
IP-EIGRP (AS 100): Topology entry for 10.0.0.0/8 State: Active, 0:01:15, Reply count: 0 Originating router: 10.1.1.1 Last sent query: 10.1.1.2
What is the root cause?
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 redistributed OSPF route is a summary that causes EIGRP queries to go unanswered, leading to SIA.
The EIGRP route for 10.0.0.0/8 is in Active state, meaning it is waiting for replies from neighbors. The redistribution from OSPF may be injecting a summary route that causes a query to be sent to all neighbors, but one neighbor may not have a route back, causing the query to be unanswered. The fix is to ensure that the redistributed routes are not summarized or to use a stub router to limit query scope.
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 redistributed OSPF route is a summary that causes EIGRP queries to go unanswered, leading to SIA.
Why this is correct
Summary routes can cause queries to propagate widely; if a neighbor has no route, the query times out.
- ✗
The EIGRP metric is too high, causing the route to be unreachable.
Why it's wrong here
Metric does not cause SIA; SIA is about query replies.
- ✗
The OSPF redistribution is missing the subnets keyword, causing classful behavior.
Why it's wrong here
Missing subnets would not cause SIA; it would affect route installation.
- ✗
The EIGRP AS number is mismatched between routers.
Why it's wrong here
AS mismatch would prevent neighbor formation, not cause SIA.
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
One of 1,966 original 300-410 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.