AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 84

A company has two redundant AWS Direct Connect connections to a VPC. The VPC is configured using BGP metrics so that one Direct Connect connection is used as the primary traffic path. The company wants the primary Direct Connect connection to fail to the secondary in less than one second.
What should be done to meet this requirement?

Answer options

• A. Configure BGP on the company's router with a keep-alive to 300 ms and the BGP hold timer to 900 ms.
• B. Enable Bidirectional Forwarding Detection (BFD) on the company's router with a detection minimum interval of 300 ms and a BFD liveness detection multiplier of 3.
• C. Enable Dead Peer Detection (DPD) on the company's router with a detection minimum interval of 300 ms and a DPD liveliness detection multiplier of 3.
• D. Enable Bidirectional Forwarding Detection (BFD) echo mode on the company's router and disable sending the Internet Control Message Protocol (ICMP) IP packet requests.

Correct answer: B

Explanation

Enabling Bidirectional Forwarding Detection (BFD) allows for rapid detection of link failures, which is necessary for the company to switch to the secondary connection in less than one second. The other options, while they may provide some level of monitoring, do not offer the same speed and efficiency in failure detection as BFD with the specified parameters.