AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 240

A company has an application VPC and a networking VPC that are connected through VPC peering. The networking VPC contains a Network Load Balancer (NLB). The application VPC contains Amazon EC2 instances that run an application. The EC2 instances are part of a target group that is associated with the NLB in the networking VPC.

The company configures a third VPC and peers it to the networking VPC. The new VPC contains a new version of the existing application. The new version of the application runs on new EC2 instances in an application subnet. The new version of the application runs in a different Availability Zone than that original version of the application.

The company needs to establish connectivity between the NLB and the new version of the application.

Which combination of steps will meet this requirement? (Choose three.)

Answer options

• A. Register the new application EC2 instances with the NLB by using the instance IDs.
• B. Register the new application EC2 instances with the NLB by using instance IP addresses.
• C. Configure the NLB in the Availability Zone where the new application EC2 instances run.
• D. Configure the NLB to use zonal shift.
• E. Configure the network ACL for the application subnet in the new VPC to allow outbound connections.
• F. Configure the network ACL for the application subnet in the new VPC to allow inbound connections and outbound connections.

Correct answer: B, C, F

Explanation

The correct answer is B, C, and F. Registering the new EC2 instances with the NLB using their IP addresses (B) is necessary because they are in a different VPC. Configuring the NLB in the Availability Zone of the new EC2 instances (C) ensures it can route traffic properly. Allowing both inbound and outbound traffic through the network ACL (F) is essential for proper communication between the services. Options A and D are incorrect as using instance IDs is not supported due to the instances being in a different VPC, and zonal shift is not required for this scenario.