AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 83

A company is deploying a new web application that uses a three-tier model with a public-facing Network Load Balancer and web servers in an Amazon VPC. The application servers are hosted in the company's data center. There is an AWS Direct Connect connection between the VPC and the company's data center. Load testing results indicate that up to 100 servers, equally distributed across multiple Availability Zones, are required to handle peak loads.
The network engineer needs to design a VPC that has a /24 CIDR assigned to it.
How should the engineer allocate subnets across three Availability Zones for each tier?

Answer options

• A. Network Load Balancer: /29 per subnet Web: /26 per subnet
• B. Network Load Balancer: /28 per subnet Web: /25 per subnet
• C. Network Load Balancer: /28 per subnet Web: /27 per subnet
• D. Network Load Balancer: /28 per subnet Web: /26 per subnet

Correct answer: D

Explanation

Option D is correct because it allows for sufficient IP addresses for the Network Load Balancer and the web servers, accommodating the need for scalability across multiple Availability Zones. The other options either allocate too few IP addresses for the web servers or do not utilize the CIDR block effectively, potentially leading to insufficient capacity during peak loads.