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

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

To distribute traffic from customers to EC2 instances in an Auto Scaling group and encrypt all traffic at all stages between the customers and the application servers without decryption at intermediate points, the company should create a Network Load Balancer (NLB) with a TCP listener and configure the Auto Scaling group to register instances with the NLB’s target group (Option C). This solution allows for end-to-end encryption of trafficwithout decryption at intermediate points.

During creation of the Auto Scaling group, select subnets for the primary network interface. Use the user data option to run a cloud-init script to allocate a second network interface and to associate an Elastic IP address from the BYOIP pool.

This solution meets all of the requirements stated in the question. The primary network interface can be configured in a private subnet during creation of the Auto Scaling group. The user data option can be used to run a cloud-init script that will allocate a second network interface and associate an Elastic IP address from the BYOIP pool with it.