300-410 Question 75
Single answerA network engineer is configuring a routing protocol on a Cisco router in a multi-vendor environment. The engineer wants to ensure that the routing protocol selects the best path based on the lowest metric value. Which of the following accurately describes how the metric calculation affects route selection in this scenario?
- A
The OSPF protocol uses cost, which is based on interface bandwidth, to determine the best path.
- B
EIGRP uses only hop count to calculate the metric, making it less granular than OSPF.
- C
BGP relies on attributes, such as local preference and AS path length, to influence best path selection.
- D
RIP selects the best path based on the lowest bandwidth value.
Show answer and explanation
Correct answer: A
Explanation
The correct answer is that OSPF uses cost, which is calculated based on interface bandwidth, to determine the best path. This concept is fundamental to understanding how routing protocols prioritize routes. Although EIGRP and BGP also calculate path preferences, they use different methods (composite metrics for EIGRP, path attributes for BGP). RIP, on the other hand, relies solely on hop count for path selection.
- A. Correct.
Correct. OSPF calculates its metric using cost, which is determined by the interface bandwidth. Lower cost values result in preferred paths.
- B. Incorrect.
Incorrect. EIGRP uses a composite metric based on bandwidth and delay (and optionally reliability and load), not just hop count.
- C. Incorrect.
Incorrect. BGP does not use a traditional metric; instead, it uses path attributes like local preference and AS path length for route selection.
- D. Incorrect.
Incorrect. RIP selects the best path based on the lowest hop count, not bandwidth.