AWS Certified Solutions Architect – Associate (SAA-C03) — Question 126

A medical records company is hosting an application on Amazon EC2 instances. The application processes customer data files that are stored on Amazon S3. The EC2 instances are hosted in public subnets. The EC2 instances access Amazon S3 over the internet, but they do not require any other network access.
A new requirement mandates that the network traffic for file transfers take a private route and not be sent over the internet.
Which change to the network architecture should a solutions architect recommend to meet this requirement?

Answer options

• A. Create a NAT gateway. Configure the route table for the public subnets to send traffic to Amazon S3 through the NAT gateway.
• B. Configure the security group for the EC2 instances to restrict outbound traffic so that only traffic to the S3 prefix list is permitted.
• C. Move the EC2 instances to private subnets. Create a VPC endpoint for Amazon S3, and link the endpoint to the route table for the private subnets.
• D. Remove the internet gateway from the VPC. Set up an AWS Direct Connect connection, and route traffic to Amazon S3 over the Direct Connect connection.

Correct answer: C

Explanation

The correct answer is C because moving the EC2 instances to private subnets and creating a VPC endpoint for Amazon S3 allows the instances to access S3 without routing traffic over the public internet, fulfilling the requirement for private network traffic. Option A is incorrect as a NAT gateway is not needed for S3 access; Option B does not ensure private routing; and Option D complicates the architecture unnecessarily without guaranteeing private S3 access.