AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 74

A company has hundreds of VPCs on AWS. All the VPCs access the public endpoints of Amazon S3 and AWS Systems Manager through NAT gateways. All the traffic from the VPCs to Amazon S3 and Systems Manager travels through the NAT gateways. The company's network engineer must centralize access to these services and must eliminate the need to use public endpoints.

Which solution will meet these requirements with the LEAST operational overhead?

Answer options

• A. Create a central egress VPC that has private NAT gateways. Connect all the VPCs to the central egress VPC by using AWS Transit Gateway. Use the private NAT gateways to connect to Amazon S3 and Systems Manager by using private IP addresses.
• B. Create a central shared services VPC. In the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Ensure that private DNS is turned off. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Create an Amazon Route 53 forwarding rule for each interface VPC endpoint. Associate the forwarding rules with all the VPCs. Forward DNS queries to the interface VPC endpoints in the shared services VPC.
• C. Create a central shared services VPIn the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Ensure that private DNS is turned off. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Create an Amazon Route 53 private hosted zone with a full service endpoint name for Amazon S3 and Systems Manager. Associate the private hosted zones with all the VPCs. Create an alias record in each private hosted zone with the full AWS service endpoint pointing to the interface VPC endpoint in the shared services VPC.
• D. Create a central shared services VPC. In the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Ensure that private DNS is turned on for the interface VPC endpoints and that the transit gateway is created with DNS support turned on.

Correct answer: C

Explanation

Option C is correct because it effectively centralizes access to Amazon S3 and Systems Manager by using interface VPC endpoints and a private hosted zone, reducing dependency on public endpoints while allowing private communication. Options A, B, and D do not provide the optimal combination of centralized access and minimal operational overhead, particularly as they involve either public DNS configurations or additional management complexity.