Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A router learns the same destination from EIGRP and OSPF. The EIGRP route has a metric of 1000, and the OSPF route has a metric of 10. Which route is installed by default?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
The OSPF route, because 10 is lower than 1000
This is wrong because metrics from different protocols are not compared directly until administrative distance is considered.
B
Best answer
The EIGRP route, because its source has a lower default administrative distance
This is correct because EIGRP is preferred over OSPF by default due to administrative distance.
C
Distractor review
Both routes automatically install for load balancing
This is wrong because routes from different protocols are not automatically load-balanced simply because they reach the same destination.
D
Distractor review
Neither route installs until the administrator chooses manually
This is wrong because the router can select a preferred route automatically using its normal decision process.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is to assume that the route with the numerically lowest metric is always preferred, regardless of the routing protocol. In this question, the OSPF route has a metric of 10, which looks better than the EIGRP metric of 1000. However, metrics from different protocols are not directly comparable. The router first compares administrative distance, which rates the trustworthiness of the routing source. Since EIGRP’s default administrative distance (90) is lower than OSPF’s (110), the router installs the EIGRP route despite its higher metric. This trap tests your understanding of routing protocol preference, not just metric values.
Technical deep dive
How to think about this question
Routing protocols like EIGRP and OSPF use different metrics to evaluate the best path to a destination. EIGRP uses a composite metric based on bandwidth, delay, reliability, load, and MTU, while OSPF uses cost calculated from interface bandwidth. However, these metrics are only comparable within the same routing protocol. When a router learns routes to the same destination from different protocols, it must use a higher-level decision factor to choose which route to install in the routing table. The router uses administrative distance (AD) as the primary criterion to select between routes learned from different routing protocols. Administrative distance is a value that rates the trustworthiness of a routing source, with lower values being more preferred. By default, EIGRP internal routes have an AD of 90, while OSPF routes have an AD of 110. Therefore, even if the OSPF metric is numerically lower, the router prefers the EIGRP route because its source is considered more reliable. This behavior often confuses candidates who compare metrics directly across protocols without considering administrative distance first. The exam trap lies in assuming that a lower metric always means a better route, which is only true within the same routing protocol. In practical networks, understanding administrative distance ensures predictable routing behavior and helps avoid routing loops or suboptimal path selection when multiple protocols coexist.
KKey Concepts to Remember
- A router uses administrative distance to select the preferred route when multiple routing protocols provide routes to the same destination.
- Administrative distance is a trustworthiness value where lower numbers indicate more preferred routing sources.
- EIGRP internal routes have a default administrative distance of 90, which is lower than OSPF’s default of 110.
- Routing protocol metrics are only comparable within the same protocol and do not determine route preference across different protocols.
- The router installs the route with the lowest administrative distance regardless of the metric values from different routing protocols.
- Comparing metrics directly between EIGRP and OSPF without considering administrative distance leads to incorrect route selection assumptions.
- When multiple protocols provide routes, the router’s decision process first evaluates administrative distance before considering metrics.
- Understanding administrative distance prevents routing loops and ensures predictable routing behavior in multi-protocol environments.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
A router uses administrative distance to select the preferred route when multiple routing protocols provide routes to the same destination.
What is the correct answer to this question?
The correct answer is: The EIGRP route, because its source has a lower default administrative distance — The EIGRP route is installed by default because route selection between different routing protocols is based on administrative distance before the protocol-specific metric is compared across sources. In plain language, the router does not compare an OSPF metric of 10 directly against an EIGRP metric of 1000 because those metrics come from different systems and are not numerically comparable in a meaningful cross-protocol way. Instead, the router first looks at the trustworthiness of the source. By default, internal EIGRP routes have a lower administrative distance than OSPF routes, so EIGRP wins even though the OSPF metric value appears lower. This is a classic CCNA trap designed to catch people who compare metrics across different protocols without considering administrative distance first.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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