mediumMultiple Choice
300-410 Practice Question: An engineer is troubleshooting a route…
An engineer is troubleshooting a route redistribution issue between OSPF and EIGRP. R1 runs both protocols and redistributes OSPF into EIGRP. The engineer notices that OSPF routes redistributed into EIGRP have an AD of 170, but some routes from OSPF are not being redistributed. What is the most likely cause?
⚠ Common exam trap
300-410 often tests the misconception that redistribution pulls routes from the protocol database — candidates forget that only routes present in the routing table can be redistributed, so an AD conflict can silently block redistribution.
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 OSPF routes are not in the routing table because they are overridden by a static route with AD 1.
Route redistribution only advertises routes that are present in the routing table. If an OSPF route is overridden by a static route with AD 1 (static routes have AD 1 by default, which is better than OSPF's 110), the OSPF route is not installed in the RIB. Consequently, the redistribution process has nothing to redistribute for that prefix, and it will not appear in EIGRP. This is a classic redistribution gotcha: the source protocol must have the route in its routing table for redistribution to work.
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 routes have a higher metric than the EIGRP routes.
Why it's wrong here
Metric values do not block redistribution; the OSPF routes are likely missing from the routing table because they are not in the OSPF database or are filtered by a route-map or distribute-list. Metric comparison is tempting because seed metrics matter when redistributing into EIGRP, but that governs preference, not whether routes appear.
- ✓
The OSPF routes are not in the routing table because they are overridden by a static route with AD 1.
Why this is correct
Redistribution only advertises routes present in the routing table. A static route with administrative distance 1 is preferred over the OSPF-learned route, so that prefix never enters the table and cannot be redistributed into EIGRP, explaining why some OSPF routes are missing.
- ✗
The redistribute ospf 1 metric 10000 command is missing.
Why it's wrong here
Omitting the metric in a redistribute statement causes the command to be rejected or the routes to be excluded entirely, which would affect all OSPF routes rather than only some. The metric keyword is correctly used when seeding redistributed routes into EIGRP.
- ✗
The OSPF routes are external type 2, which are not redistributed by default.
Why it's wrong here
OSPF external type 2 routes are redistributed into EIGRP like any other OSPF route; the E2 designation affects OSPF metric calculation only. This distinction matters when tuning OSPF cost or path preference, not when filtering redistribution.
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
Learn chapter
ACL-Based Traffic Filtering and Policy-Based Routing
Key term
Route Redistribution Between Protocols
Route redistribution between protocols is the process of taking routes learned from one routing protocol and injecting them into another routing protocol so that networks using different protocols can communicate.
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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.