AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 125

You have just provisioned a new VPC a with a CIDR block of 172.16.12.0/24. The entire CIDR block is fully utilized by subdividing it into 6 subnets, we will refer to these as Subnet1 through to Subnet6. The first 2 subnets (Subnet1 and Subnet2) are the same size. The last 4 subnets (Subnet3, Subnet4, Subnet5, Subnet6) are also the same size. Subnet5 is half the size of Subnet2. The address space as occupied by the first two subnets is contiguous, as is the address space occupied by the last 4 subnets. Within Subnet3 AWS reserves the address 172.16.12.129 for the VPC router.
Select the correct IP address reserved by AWS for DNS in the Subnet2.

Answer options

Correct answer: C

Explanation

The correct answer is C, 172.16.12.66, which is reserved for DNS in Subnet2 based on the subnetting scheme described. Options A and B are invalid as they fall outside the CIDR block of the VPC. Option D, while within the range, does not adhere to the specified DNS IP assignment for Subnet2.