Which of the following changes should the Solutions Architect recommend to make this solution more secure without impeding application’s performance?
Add a NAT gateway. Update the security groups on the EC2 instance to allow access to and from the S3 IP range only. Configure an S3 bucket policy that allows communication from the NAT gateway’s Elastic IP address only.
Add a VPC endpoint. Configure endpoint policies on the VPC endpoint to allow access to the required Amazon S3 buckets only. Implement an S3 bucket policy that allows communication from the VPC’s source IP range only.
Add a NAT gateway. Update the security groups on the EC2 instance to allow access to and from the S3 IP range only. Configure an S3 bucket policy that allows communication from the source public IP address of the on-premises network only.
Add a VPC endpoint. Configure endpoint policies on the VPC endpoint to allow access to the required S3 buckets only. Implement an S3 bucket policy that allows communication from the VPC endpoint only.
Explanations:
A NAT gateway is not necessary for secure access to Amazon S3 and would introduce additional costs. S3 access control via IP range in security groups is not a best practice, as IPs can change.
While a VPC endpoint improves security by keeping traffic within AWS, configuring a bucket policy based on source IP range is not ideal. The VPC endpoint should control access, not the source IP range.
Restricting access based on public IP range of the on-premises network is not ideal, as IP addresses can change. A NAT gateway is also unnecessary and does not improve security for accessing S3.
A VPC endpoint ensures that S3 access stays within AWS, and endpoint policies control access to specific buckets. An S3 bucket policy that allows access from the VPC endpoint ensures that only authorized traffic reaches the S3 bucket.
I figure that the answer is:
Add a VPC endpoint. Configure endpoint policies on the VPC endpoint to allow access to the required S3 buckets only. Implement an S3 bucket policy that allows communication from the VPC endpoint only.