CCNA IP Routing Practice Question
A route to 10.10.10.0/24 is learned through two OSPF paths. Both have the same prefix length and the same administrative distance, but one path has a lower OSPF metric. Which path is preferred?
⚠ Common exam trap
Remember, administrative distance only matters when comparing different routing protocols, not when choosing between paths within the same protocol.
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 path with the lower OSPF metric
The path with the lower OSPF metric is preferred. In practical terms, when the prefix and route source are the same, the router uses the routing protocol’s internal path-selection logic. For OSPF, the lower metric is the more attractive path. This is a clean example of metric-based selection within one routing protocol. Administrative distance is not the deciding factor here because the source protocol is the same on both paths.
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 path with the lower OSPF metric
Why this is correct
OSPF calculates a metric, called cost, as the sum of outgoing interface costs along a path, and the SPF algorithm identifies the lowest-cost path to a destination. When two OSPF paths exist for the same 10.10.10.0/24 prefix, the route with the lower cost is installed in the routing table because it represents the shortest or most efficient path. Since both routes come from OSPF, their administrative distance is identical, so the OSPF metric is the sole determining factor.
- ✗
The path with the higher OSPF metric
Why it's wrong here
Selecting the path with the higher OSPF metric would contradict OSPF's SPF calculation, which always chooses the least-cost path to a destination. A higher cost indicates a less desirable route, such as one traversing slower or more numerous links, and OSPF will never prefer it over a lower-cost alternative for the same prefix. The only time a higher-metric path is used is if the lower-metric path is absent from the routing table.
When this WOULD be correct
In a different question, if the context specified that the routing protocol was using a different metric system where a higher metric indicated a better path (such as a custom metric configuration), then this option could be correct. For example, a question might state that a specific implementation of OSPF has been modified to prioritize higher metrics for certain traffic types.
- ✗
Both paths equally, because the administrative distance is the same
Why it's wrong here
Administrative distance is a Cisco-specific trust rating assigned to the routing protocol as a whole, not a per-path metric for selecting among OSPF routes. When two OSPF paths to the same prefix have unequal metrics, the router compares the OSPF cost values directly, and the lower-cost path wins. Equal AD only means both routes are equally trusted as OSPF-learned; it does not enable load balancing, which would require the OSPF metrics to be exactly equal.
When this WOULD be correct
In a different scenario where a routing protocol allows for equal-cost multipath routing and treats multiple paths with the same metric and administrative distance as equally valid, this option would be correct. For example, if the question specified that the routing protocol supports load balancing, then both paths could be considered equally preferred.
- ✗
Neither path, because two OSPF routes to the same prefix are invalid
Why it's wrong here
OSPF is fully capable of learning the same prefix through multiple paths, as occurs in redundant OSPF networks where the SPF algorithm evaluates all available routes. Having two OSPF routes to 10.10.10.0/24 is not invalid; rather, OSPF processes them and selects the one with the lowest metric for installation in the routing table, while potentially keeping equal-cost paths for ECMP. Discarding both routes would leave the network without a route, which OSPF would never do if any path exists.
When this WOULD be correct
In a question where it states that OSPF does not support multiple equal-cost paths for a specific configuration or that the routing table has a restriction preventing multiple entries for the same prefix, this option could be correct.
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 path with the lower OSPF metricCorrect answer▾
Why this is correct
OSPF calculates a metric, called cost, as the sum of outgoing interface costs along a path, and the SPF algorithm identifies the lowest-cost path to a destination. When two OSPF paths exist for the same 10.10.10.0/24 prefix, the route with the lower cost is installed in the routing table because it represents the shortest or most efficient path. Since both routes come from OSPF, their administrative distance is identical, so the OSPF metric is the sole determining factor.
✗The path with the higher OSPF metricWrong answer — click to see why▾
Why this is wrong here
A higher OSPF metric indicates a less desirable path, as OSPF uses cost as its metric where lower cost is preferred. Selecting a higher metric path would contradict the fundamental routing principle of choosing the best path based on lowest metric.
★ When this WOULD be the correct answer
In a different question, if the context specified that the routing protocol was using a different metric system where a higher metric indicated a better path (such as a custom metric configuration), then this option could be correct. For example, a question might state that a specific implementation of OSPF has been modified to prioritize higher metrics for certain traffic types.
Why candidates choose this
Students might confuse metric with other attributes like administrative distance or think that a higher metric indicates a more reliable path, but in OSPF, higher cost means less preferred.
✗Both paths equally, because the administrative distance is the sameWrong answer — click to see why▾
Why this is wrong here
Equal administrative distance does not imply equal preference when metrics differ. The router compares metrics within the same routing protocol; if metrics are different, the lower metric path is chosen, not both.
★ When this WOULD be the correct answer
In a different scenario where a routing protocol allows for equal-cost multipath routing and treats multiple paths with the same metric and administrative distance as equally valid, this option would be correct. For example, if the question specified that the routing protocol supports load balancing, then both paths could be considered equally preferred.
Why candidates choose this
Test-takers may mistakenly believe that equal administrative distance automatically leads to load balancing, but load balancing requires equal metrics, not just equal AD.
✗Neither path, because two OSPF routes to the same prefix are invalidWrong answer — click to see why▾
Why this is wrong here
OSPF can learn the same prefix via multiple paths; this is normal. The router selects the best path based on metric, and the other paths are kept in the routing table as backup or for equal-cost load balancing if metrics are equal.
★ When this WOULD be the correct answer
In a question where it states that OSPF does not support multiple equal-cost paths for a specific configuration or that the routing table has a restriction preventing multiple entries for the same prefix, this option could be correct.
Why candidates choose this
Some students might think that duplicate routes cause errors, but OSPF handles multiple paths gracefully and selects the best one.
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
Interpreting HSRP and VRRP Operational Status
Key term
Prefix length
A prefix length is the number of bits in a subnet mask that identifies the network portion of an IP address, written after a slash (e.g., /24).
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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JA
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.