AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 182

A company is building an API-based application on AWS and is using a microservices architecture for the design. The company is using a multi-account AWS environment that includes a separate AWS account for each microservice development team. Each team hosts its microservice in its own VPC that contains Amazon EC2 instances behind a Network Load Balancer (NLB).

A network engineer needs to use Amazon API Gateway in a shared services account to create an HTTP API to expose these microservices to external applications. The network engineer must ensure that access to the microservices can occur only over a private network. Additionally, the company must be able to control which entities from its internal network can connect to the microservices. In the future, the company will create more microservices that the company must be able to integrate with the application.

What is the MOST secure solution that meets these requirements?

Answer options

• A. Create an Application Load Balancer (ALB) in a VPC in the shared services account. Configure the integration to the API Gateway API by using a VPC link. Associate the VPC link with the ALB. Create a VPC endpoint service in each microservice account. Create an AWS PrivateLink endpoint for those services in the shared services account. Add the elastic network interface IP addresses of the VPC endpoint as targets for the target group of the ALB.
• B. Create an Application Load Balancer (ALB) in a VPC in the shared services account. Configure the integration to the API Gateway API by using a VPC link. Associate the VPC link with the ALConnect all the VPCs to each other by using a central transit gateway. Add the IP addresses of the NLB as IP-based targets in the ALB target group.
• C. Configure the integration to the API Gateway API by using HTTP-based integration. Connect all the VPCs to each other by using a central transit gateway. Create a separate HTTP integration to each NLB for each microservice. Add the HTTP endpoint of the NLB as the endpoint URL in the HTTP integration.
• D. Configure the integration to the API Gateway API by using VPC link integration. Connect all the VPCs to each other by using a central transit gateway. Create a separate VPC link to each NLB for each microservice. Add the HTTP endpoint of the NLB as the endpoint URL in the VPC link integration.

Correct answer: A

Explanation

The correct answer is A because it ensures a secure connection through AWS PrivateLink and VPC endpoint services, allowing only private network access to the microservices. Options B and C do not utilize AWS PrivateLink, which is crucial for private connectivity, while option D does not offer the same level of control and security as A, making it less ideal for the requirements.