200-301 Question 287
Single answerA network engineer is configuring routing on a network with both OSPF and EIGRP running. The engineer notices that a route to the 10.10.10.0/24 network is present in both routing protocols. However, only the EIGRP route is installed in the routing table. Why is the EIGRP route preferred over OSPF?
- A
EIGRP has a lower administrative distance than OSPF.
- B
EIGRP uses hop count as its primary metric, which is faster to calculate.
- C
OSPF routes are always less reliable than EIGRP routes.
- D
EIGRP supports only classful routing, which improves its performance over OSPF.
Show answer and explanation
Correct answer: A
Explanation
When multiple routing protocols offer the same route, the router uses the administrative distance (AD) to choose the most trustworthy source. EIGRP has a lower default administrative distance (90) compared to OSPF (110), so the EIGRP route is installed in the routing table instead of the OSPF route.
- A. Correct.
Correct. EIGRP has a default administrative distance of 90 for internal routes, while OSPF has a default administrative distance of 110. The route with the lower administrative distance is preferred.
- B. Incorrect.
Incorrect. While EIGRP uses a composite metric based on bandwidth and delay, hop count is not its primary metric. Additionally, the metric itself does not determine the preference between routing protocols; administrative distance does.
- C. Incorrect.
Incorrect. OSPF is a reliable and widely used routing protocol, and its reliability does not impact the preference of EIGRP in this scenario.
- D. Incorrect.
Incorrect. EIGRP supports both classful and classless routing, and this fact does not play a role in determining route preference in this case.