What is a CIDR block for this VPC that results in the smallest usable private IP address range?

Refer to the exhibit.

An organization is sizing an Anypoint VPC for the non-production deployments of those Mule applications that connect to the organization’s on-premises systems. This applies to approx. 60 Mule applications. Each application is deployed to two CloudHub i workers. The organization currently has three non-production environments (DEV, SIT and UAT) that share this VPC. The AWS region of the VPC has two AZs.

The organization has a very mature DevOps approach which automatically progresses each application through all non-production environments before automatically deploying to production.

This process results in several Mule application deployments per hour, using CloudHub’s normal zero-downtime deployment feature.

What is a CIDR block for this VPC that results in the smallest usable private IP address range?
A . 10.0.0.0/26 (64 IPS)
B . 10.0.0.0/25 (128 IPs)
C . 10.0.0.0/24 (256 IPs)
D . 10.0.0.0/22 (1024 IPs)

Answer: D

Explanation:

Mule applications are deployed in CloudHub workers and each worker is assigned with a dedicated IP

• For zero downtime deployment, each worker in CloudHub needs additional IP addresses

• A few IPs in a VPC are reserved for infrastructure (generally 2 IPs)

• The IP addresses are usually in a private range with a subnet block specifier, such as 10.0.0.1/24

• The smallest CIDR network subnet block you can assign for your VPC is /24 (256 IP addresses) (60*3 env * 2 worker per application) + 50% of (total) for zero downtime = 540 In this case correct answer is 10.0.0.0/22 as this provided 1024 IP’s. Other IP’s are insufficient.