ANS-C01 Exam Dumps : Amazon AWS Certified Advanced Networking - Specialty

Option C provides a secure and scalable solution using VPC endpoint services powered by AWS PrivateLink. AWS PrivateLink enables private connectivity between VPCs and services without exposing the data to the public internet or using a VPN connection. By creating VPC endpoints in each application VPC, the company can securely access the central shared services VPC without the need for complex network configurations. Furthermore, PrivateLink supports cross-account connectivity, which makes it a scalable solution as more business units consume data from the central shared services VPC in the future.

Setting up an AWS Site-to-Site VPN connection between on premises and AWS would enable a secure and encrypted connection over the public internet1. Deploying an Amazon Route 53 Resolver outbound endpoint in the Region that is hosting the VPC would enable forwarding of DNS queries for on-premises servers to the on-premises DNS servers2. This would allow EC2 instances in the VPC to resolve names of on-premises servers during the migration period. After the migration period, the Route 53 Resolver outbound endpoint can be deleted with minimal configuration changes.

The most operationally efficient way to restrict inbound traffic to the ALB to come from CloudFront is to use the AWS managed prefix list for CloudFront. A prefix list is a collection of CIDR blocks that can be used to configure security groups and network ACLs. AWS provides a managed prefix list for CloudFront that is automatically updated when CloudFront IP ranges change. By adding an inbound rule to the ALB’s security group to allow the AWS managed prefix list for CloudFront, the network engineer can ensure that only CloudFront can access the ALB at the network layer. This solution does not require any additional configuration or maintenance. Option B is less efficient because network ACLs are stateless and require rules for both inbound and outbound traffic. Option C is not a network layer solution, but an application layer solution that requires the ALB to inspect the HTTP headers and reject requests that do not have the custom header. Option D is also not a network layer solution, but a web layer solution that requires AWS WAF to filter the traffic based on the CloudFront IP set. This solution also requires an AWS Lambda function to update the CloudFront IP set, which adds complexity and cost