Explanation
Correct Answer: B - Set up a gateway VPC endpoint for Amazon S3 in the VPC.
Why this is correct:
- VPC Endpoints for S3: AWS provides VPC endpoints specifically for Amazon S3 that allow EC2 instances within a VPC to access S3 buckets without traversing the public internet.
- Traffic stays within AWS network: Gateway VPC endpoints for S3 use AWS's private network infrastructure, ensuring traffic never leaves AWS's network and doesn't go over the public internet.
- Security and compliance: This approach meets the requirement that "traffic must not traverse the internet" as it keeps all traffic within AWS's private network.
- No internet gateway required: Unlike NAT gateways, VPC endpoints don't require internet gateways or NAT devices.
Why other options are incorrect:
A. Create a private hosted zone by using Amazon Route 53.
- Private hosted zones are for DNS resolution within a VPC, not for creating private network connections to S3.
- This doesn't prevent internet traversal for S3 traffic.
C. Configure the EC2 instances to use a NAT gateway to access the S3 bucket.
- NAT gateways route traffic through the internet, which violates the requirement that traffic must not traverse the internet.
- While NAT gateways provide outbound internet access, they still use the public internet to reach S3.
D. Establish an AWS Site-to-Site VPN connection between the VPC and the S3 bucket.
- Site-to-Site VPN connections are for connecting VPCs to on-premises networks, not for connecting to AWS services like S3.
- S3 doesn't support direct VPN connections; you need VPC endpoints instead.
Key AWS Concepts:
- VPC Endpoints: Private connections between your VPC and supported AWS services without using internet gateways, NAT devices, VPN connections, or AWS Direct Connect.
- Gateway VPC Endpoint: Specifically for Amazon S3 and DynamoDB, these are gateway endpoints that route traffic to AWS services through AWS's private network.
- Interface VPC Endpoint: Uses AWS PrivateLink for other AWS services, providing private IP addresses in your VPC.
Best Practice: Always use VPC endpoints for accessing AWS services from within a VPC when you need to keep traffic within AWS's network for security, compliance, or performance reasons.
