Question 290 of 1,389
CCNA IP Routing Practice Question
A router learns 10.10.10.0/24 from OSPF and EIGRP at the same time. OSPF reports a metric of 20, and EIGRP reports a metric of 30720. Which route is installed in the routing table by default?
⚠ Common exam trap
Remember, administrative distance is the first criterion for route selection between different protocols, not the metric.
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 EIGRP route, because its administrative distance is lower
When the same prefix is learned from different routing protocols, the router compares administrative distance first. EIGRP internal routes use AD 90, while OSPF uses AD 110, so the EIGRP route is preferred.
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, because 20 is lower than 30720
Why it's wrong here
OSPF cost and the EIGRP composite metric are measured on entirely different scales; OSPF cost is a link-derived value while EIGRP uses bandwidth, delay, load, and reliability. Comparing 20 against 30720 across protocols is invalid because metric comparison is only meaningful between routes learned by the same routing protocol. When OSPF and EIGRP both advertise 10.10.10.0/24, the router ignores metric numbers and first compares administrative distance, so EIGRP's AD of 90 beats OSPF's 110.
When this WOULD be correct
In a different scenario where the question specifies that both OSPF and EIGRP routes have the same administrative distance, and the metrics are the only factor considered, then the OSPF route would be chosen due to its lower metric of 20 compared to EIGRP's 30720.
- ✓
The EIGRP route, because its administrative distance is lower
Why this is correct
Routers prioritise routes for the same destination using administrative distance (AD) before considering protocol metrics. EIGRP has a default administrative distance of 90, which is lower than OSPF's default of 110. Consequently, even though OSPF reports a numerically lower metric, the router will install the EIGRP route for 10.10.10.0/24 into its routing table because its superior administrative distance takes precedence.
- ✗
Both routes, because they point to the same prefix
Why it's wrong here
Simply matching the destination prefix does not create equal-cost load balancing. Cisco routers require multiple routes for the same prefix to have identical administrative distance and metric before they can be installed as parallel paths, and different routing protocols have distinct default ADs. Here, OSPF's AD of 110 and EIGRP's AD of 90 make the routes unequal, so only the EIGRP route is installed in the routing table.
When this WOULD be correct
In a different scenario where the question states that the router is configured to support equal-cost multi-path (ECMP) routing, both OSPF and EIGRP routes could be installed in the routing table, allowing for load balancing across the same prefix.
- ✗
Neither route, because the metrics are not comparable
Why it's wrong here
The fact that OSPF and EIGRP metrics are not comparable does not stall route selection; the router never tries to compare them directly. Instead, the Cisco route-selection process starts by choosing the lowest administrative distance among all routing protocols that know the prefix. Since EIGRP's AD (90) is lower than OSPF's (110), the EIGRP route is installed, and the OSPF route is simply ignored for this destination.
When this WOULD be correct
In a scenario where a question states that both OSPF and EIGRP routes are being considered but specifies that the routing protocols are configured to ignore metrics due to a policy or misconfiguration, then it could be correct to say neither route is installed because the metrics are not comparable.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓The EIGRP route, because its administrative distance is lowerCorrect answer▾
Why this is correct
Routers prioritise routes for the same destination using administrative distance (AD) before considering protocol metrics. EIGRP has a default administrative distance of 90, which is lower than OSPF's default of 110. Consequently, even though OSPF reports a numerically lower metric, the router will install the EIGRP route for 10.10.10.0/24 into its routing table because its superior administrative distance takes precedence.
✗The OSPF route, because 20 is lower than 30720Wrong answer — click to see why▾
Why this is wrong here
Metrics from different routing protocols are not comparable because each protocol uses its own metric calculation (e.g., OSPF uses cost based on bandwidth, EIGRP uses composite metric based on bandwidth and delay). The router uses administrative distance to choose between routes from different protocols, not metric values.
★ When this WOULD be the correct answer
In a different scenario where the question specifies that both OSPF and EIGRP routes have the same administrative distance, and the metrics are the only factor considered, then the OSPF route would be chosen due to its lower metric of 20 compared to EIGRP's 30720.
Why candidates choose this
Students often mistakenly think that the route with the lower metric is always preferred, regardless of protocol. Since 20 is much smaller than 30720, it seems logical to choose the OSPF route, but this ignores the administrative distance tie-breaking rule.
✗Both routes, because they point to the same prefixWrong answer — click to see why▾
Why this is wrong here
A router installs only the best route to a destination in the routing table, unless equal-cost load balancing is configured. Since OSPF and EIGRP have different administrative distances, only the route with the lower AD is installed. Both routes cannot be installed simultaneously for the same prefix.
★ When this WOULD be the correct answer
In a different scenario where the question states that the router is configured to support equal-cost multi-path (ECMP) routing, both OSPF and EIGRP routes could be installed in the routing table, allowing for load balancing across the same prefix.
Why candidates choose this
Students may think that if two routes point to the same network, they can both be used for load balancing. However, load balancing requires equal metrics from the same routing protocol or equal administrative distances, which is not the case here.
✗Neither route, because the metrics are not comparableWrong answer — click to see why▾
Why this is wrong here
The router does compare routes from different protocols using administrative distance, not metrics. Since the metrics are from different protocols, they are not directly comparable, but the router still selects one route based on AD. Therefore, one route will be installed.
★ When this WOULD be the correct answer
In a scenario where a question states that both OSPF and EIGRP routes are being considered but specifies that the routing protocols are configured to ignore metrics due to a policy or misconfiguration, then it could be correct to say neither route is installed because the metrics are not comparable.
Why candidates choose this
The statement that metrics are not comparable is true, but it leads to the incorrect conclusion that no route is selected. Students may forget that administrative distance is the tie-breaker when metrics are incomparable.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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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Last reviewed: May 17, 2026
This 200-301 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 200-301 exam.
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