AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 178

A network engineer configures a second AWS Direct Connect connection to an existing network. The network engineer runs a test in the AWS Direct Connect Resiliency Toolkit on the connections. The test produces a failure. During the failover event, the network engineer observes a 90-second interruption before traffic shifts to the failover connection.

Which solution will reduce the time for failover?

Answer options

• A. Decrease the BGP hello timer to 5 seconds.
• B. Add a VPN connection to the connectivity solution. Implement fast failover.
• C. Configure Bidirectional Forwarding Detection (BFD) on the on-premises router.
• D. Decrease the BGP hold-down timer to 5 seconds.

Correct answer: C

Explanation

Configuring Bidirectional Forwarding Detection (BFD) on the on-premises router allows for quicker detection of link failures, thereby reducing the failover time. Lowering the BGP hello timer (option A) or hold-down timer (option D) can help, but they do not provide the same level of rapid failure detection as BFD. Adding a VPN connection (option B) may improve redundancy but does not directly address the failover timing issue.