AWS Certified Solutions Architect – Professional — Question 134

A company is designing a new highly available web application on AWS. The application requires consistent and reliable connectivity from the application servers in AWS to a backend REST API hosted in the company's on-premises environment. The backend connection between AWS and on-premises will be routed over an AWS Direct Connect connection through a private virtual interface. Amazon Route 53 will be used to manage private DNS records for the application to resolve the IP address on the backend REST API.
Which design would provide a reliable connection to the backend API?

Answer options

• A. Implement at least two backend endpoints for the backend REST API, and use Route 53 health checks to monitor the availability of each backend endpoint and perform DNS-level failover.
• B. Install a second Direct Connect connection from a different network carrier and attach it to the same virtual private gateway as the first Direct Connect connection.
• C. Install a second cross connect for the same Direct Connect connection from the same network carrier, and join both connections to the same link aggregation group (LAG) on the same private virtual interface.
• D. Create an IPSec VPN connection routed over the public internet from the on-premises data center to AWS and attach it to the same virtual private gateway as the Direct Connect connection.

Correct answer: B

Explanation

Option B is correct because installing a second Direct Connect connection from a different network carrier increases redundancy and reliability for the backend API connection. The other options either do not enhance reliability effectively (A), do not provide sufficient redundancy (C), or introduce a less reliable method of connection over the public internet (D).