200-301 Question 282
Single answerA network engineer is troubleshooting a routing issue on a network. The router has learned about the 192.168.10.0/24 network from two sources: OSPF with a metric of 20 and an EIGRP route with a feasible distance of 50. Both routes are valid and active in the routing table. Which route will the router use to forward packets to the 192.168.10.0/24 network?
- A
The OSPF route, because it has a lower metric.
- B
The OSPF route, because it has a lower administrative distance.
- C
The EIGRP route, because it has a lower feasible distance.
- D
The EIGRP route, because it has a lower administrative distance.
Show answer and explanation
Correct answer: D
Explanation
Administrative distance is a measure of trustworthiness for a routing protocol. When a router learns about the same network from multiple sources, it selects the route with the lowest administrative distance, regardless of the metrics of the protocols. In this scenario, EIGRP has an administrative distance of 90, which is lower than OSPF's administrative distance of 110. Therefore, the EIGRP route is preferred.
- A. Incorrect.
Incorrect. While OSPF has a lower metric in this scenario, the router first evaluates administrative distance before considering metrics.
- B. Incorrect.
Incorrect. OSPF has a higher administrative distance (110) compared to EIGRP (90), so it will not be preferred.
- C. Incorrect.
Incorrect. Feasible distance is specific to EIGRP and is not used when comparing routes from different protocols.
- D. Correct.
Correct. EIGRP has a lower administrative distance (90) than OSPF (110), so the router will prefer the EIGRP route.