CCNA IP Routing Practice Question
A router receives two routes to 10.50.0.0/16: one from OSPF and one static route with an administrative distance of 90. Which route is installed by default?
⚠ Common exam trap
A frequent exam trap is assuming that dynamic routing protocols like OSPF always override static routes regardless of administrative distance. Many candidates mistakenly believe that static routes only win if they use the default AD of 1. However, if a static route is manually assigned an AD lower than OSPF's default 110, it becomes the preferred route. This misunderstanding leads to incorrect answers because the exam tests knowledge of how administrative distance influences route selection, not just the routing protocol type. Remember, the router always chooses the route with the lowest administrative distance, even if it is a static route with a custom AD.
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 static route, because its administrative distance is lower than OSPF's
By default, the static route with administrative distance 90 is installed because it is preferred over the OSPF route with default administrative distance 110. In plain language, the router is being told that the manually configured route is more trustworthy than the OSPF-learned one, so it chooses the static path first. The protocol type alone does not decide the outcome. Administrative distance is the key comparison when two different route sources offer the same destination prefix length. This is a classic routing-selection question because many learners incorrectly assume OSPF always wins over static routes unless the static route uses the default administrative distance. Once the static route is given a value lower than OSPF’s 110, it becomes the preferred path unless a more specific route exists elsewhere.
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 static route, because its administrative distance is lower than OSPF's
Why this is correct
The static route is correct because its administrative distance is 90, which is lower than OSPF's default of 110. The router compares administrative distance values when multiple routing sources advertise the same prefix, and it installs the route with the lowest AD in the routing table. Since 90 is less than 110, the static route is preferred over the OSPF route.
- ✗
The OSPF route, because dynamic routes always override static routes
Why it's wrong here
This is wrong because a route's source—dynamic vs static—does not determine preference; instead, Cisco routers use administrative distance as the trustworthiness metric. The OSPF route has a default AD of 110, while the static route has an AD of 90, so the static route is actually more trustworthy. Dynamic routes do not always override static routes; the AD values must be compared on a case-by-case basis.
When this WOULD be correct
If the question stated that the OSPF route had a lower administrative distance than the static route, or if it specified that the static route was not installed due to a configuration issue, then this option would be correct.
- ✗
Both routes, because equal destination networks always load-balance
Why it's wrong here
This is false because load balancing only happens when multiple routes have equal administrative distance and equal metric and come from the same routing protocol or are otherwise considered equally preferred. Here, the static route has an AD of 90 and the OSPF route has an AD of 110, so they are not equally preferred. The router will install only the static route in the routing table, and traffic will not be load-balanced between them.
When this WOULD be correct
In a different scenario where both the OSPF route and static route have the same administrative distance, a question could ask which routes would be installed if load balancing is enabled. In that case, both routes could be installed for the same destination network.
- ✗
Neither route, because the destinations overlap
Why it's wrong here
This is incorrect because overlapping route announcements are routine and do not cause the router to discard either route. A router is designed to evaluate multiple routing sources and select the best path using administrative distance, not to ignore overlapping destinations. In this scenario, the static route and OSPF route overlap exactly, but the router will still pick the one with the lower AD rather than dropping both.
When this WOULD be correct
If the question stated that both routes had the same administrative distance and were configured to not allow overlapping routes, then this option would be correct. For example, if the router was configured to only accept one route for a specific destination and the routes were set to be mutually exclusive.
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 static route, because its administrative distance is lower than OSPF'sCorrect answer▾
Why this is correct
The static route is correct because its administrative distance is 90, which is lower than OSPF's default of 110. The router compares administrative distance values when multiple routing sources advertise the same prefix, and it installs the route with the lowest AD in the routing table. Since 90 is less than 110, the static route is preferred over the OSPF route.
✗The OSPF route, because dynamic routes always override static routesWrong answer — click to see why▾
Why this is wrong here
The statement is incorrect because route selection is based on administrative distance, not on whether the route is dynamic or static. OSPF's default AD is 110, which is higher than 90, so the static route is preferred.
★ When this WOULD be the correct answer
If the question stated that the OSPF route had a lower administrative distance than the static route, or if it specified that the static route was not installed due to a configuration issue, then this option would be correct.
Why candidates choose this
Students may mistakenly believe that dynamic routing protocols always override static routes due to their adaptive nature, but in Cisco IOS, static routes have a lower default AD (1) unless manually changed, and here the static route's AD is explicitly set to 90, which is still lower than OSPF's 110.
✗Both routes, because equal destination networks always load-balanceWrong answer — click to see why▾
Why this is wrong here
Load balancing only occurs when multiple routes to the same destination have equal administrative distance and equal metric. Here, the routes are from different sources with different ADs (90 vs 110), so only the best route (lowest AD) is installed.
★ When this WOULD be the correct answer
In a different scenario where both the OSPF route and static route have the same administrative distance, a question could ask which routes would be installed if load balancing is enabled. In that case, both routes could be installed for the same destination network.
Why candidates choose this
Students might think that any two routes to the same network will be load-balanced, but Cisco routers require equal AD and metric for load balancing across equal-cost paths. Different routing sources typically have different ADs, preventing load balancing.
✗Neither route, because the destinations overlapWrong answer — click to see why▾
Why this is wrong here
Overlapping routes are common and do not prevent route installation. The router selects the most specific match or, for identical prefixes, the route with the lowest administrative distance. Here, both routes are to the same prefix, so the router installs the one with lower AD.
★ When this WOULD be the correct answer
If the question stated that both routes had the same administrative distance and were configured to not allow overlapping routes, then this option would be correct. For example, if the router was configured to only accept one route for a specific destination and the routes were set to be mutually exclusive.
Why candidates choose this
A student might confuse overlapping routes with conflicting routes that cause routing loops or ambiguity, but in this case, the routes are identical in prefix length, so the router simply picks the best one based on AD.
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.
Go deeper
Related to this question
Learn chapter
OSPFv3 Single-Area Configuration for IPv6
Key term
Administrative distance
Administrative distance is a number that a router uses to decide which routing protocol's route to trust when it learns about the same destination from multiple different routing protocols.
Key term
OSPF
OSPF is a link-state routing protocol that uses the SPF algorithm to compute the shortest path to each destination within a single autonomous system.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.