AWS Certified SysOps Administrator – Associate (legacy) — Question 154

A user has created a VPC with CIDR 20.0.0.0/24. The user has created a public subnet with CIDR 20.0.0.0/25. The user is trying to create the private subnet with
CIDR 20.0.0.128/25. Which of the below mentioned statements is true in this scenario?

Answer options

• A. It will not allow the user to create the private subnet due to a CIDR overlap
• B. It will allow the user to create a private subnet with CIDR as 20.0.0.128/25
• C. This statement is wrong as AWS does not allow CIDR 20.0.0.0/25
• D. It will not allow the user to create a private subnet due to a wrong CIDR range

Correct answer: B

Explanation

The correct answer is B because the CIDR 20.0.0.128/25 is a valid range that does not overlap with the public subnet 20.0.0.0/25. Option A is incorrect as there is no CIDR overlap, C is wrong since AWS does allow the CIDR 20.0.0.0/25, and D is not valid because the CIDR range is correct.