Learn the most efficient way to add IP address space to an existing VPC in an AWS Availability Zone that has run out of capacity. Detailed explanation of the correct approach for the AWS Certified Advanced Networking – Specialty ANS-C01 exam.
Table of Contents
Question
A company ran out of IP address space in one of the Availability Zones in an AWS Region that the company uses. The Availability Zone that is out of space is assigned the 10.10.1.0/24 CIDR block. The company manages its networking configurations in an AWS CloudFormation stack. The company’ VPC is assigned the 10 10.0.0/16 CIDR block and has available capacity in the 10.10.1.0/22 CIDR block.
How should a network specialist add more IP address space in the existing VPC with the LEAST operational overhead?
A. Update the AWS::EC2::Subnet resource for the Availability Zone in the CloudFormation stack. Change the CidrBlock property to 10.10.1.0/22.
B. Update the AWS::EC2::VPC resource in the CloudFormation stack. Change the CidrBlock property to 10.10.1.0/22.
C. Copy the CloudFormation stack. Set the AWS::EC2::VPC resource CidrBlock property to 10.10.0.0/16. Set the AWS::EC2::Subnet resource CidrBlock property to 10.10.1.0/22 for the Availability Zone.
D. Create a new AWS::EC2::Subnet resource for the Availability Zone in the CloudFormation stack. Set the CidrBlock property to 10.10.2.0/24.
Answer
D. Create a new AWS::EC2::Subnet resource for the Availability Zone in the CloudFormation stack. Set the CidrBlock property to 10.10.2.0/24.
Explanation
Here’s why:
The existing VPC has a CIDR block of 10.10.0.0/16, and the Availability Zone that ran out of space was assigned 10.10.1.0/24. The company has available capacity in the 10.10.1.0/22 CIDR block.
Option A suggests updating the existing subnet’s CIDR block to 10.10.1.0/22. This would be incorrect because it overlaps with the existing 10.10.1.0/24 subnet and could cause IP conflicts.
Option B proposes changing the VPC’s CIDR block to 10.10.1.0/22. This is not the right approach because the VPC’s CIDR block should encompass all of its subnets. Changing it to a smaller range would be problematic.
Option C involves copying the entire CloudFormation stack and setting the VPC’s CIDR to 10.10.0.0/16 and the subnet’s CIDR to 10.10.1.0/22. While this would work, it requires far more operational overhead than necessary by duplicating the entire stack.
The most efficient solution is Option D. By creating a new subnet in the existing VPC and assigning it an unused CIDR range within the VPC’s address space (10.10.2.0/24), the company can add more IP capacity to the Availability Zone with minimal changes and operational impact. The new subnet is created in the same Availability Zone but does not overlap with the existing 10.10.1.0/24 subnet.
In summary, creating a new subnet resource in the existing CloudFormation stack is the best way to add IP address space to the constrained Availability Zone while minimizing operational overhead.
Amazon AWS Certified Advanced Networking – Specialty ANS-C01 certification exam assessment practice question and answer (Q&A) dump including multiple choice questions (MCQ) and objective type questions, with detail explanation and reference available free, helpful to pass the Amazon AWS Certified Advanced Networking – Specialty ANS-C01 exam and earn Amazon AWS Certified Advanced Networking – Specialty ANS-C01 certification.