AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 276

Considering the rules of IPv4 subnetting, how many subnets and hosts per subnet are possible given the following network 192.168.130.130/28? (in this question ignore the fact that AWS reserves 5 IP addresses)

Answer options

• A. 8 subnets and 30 hosts per subnet
• B. 16 subnets and 14 hosts per subnet
• C. 32 subnets and 30 hosts per subnet
• D. 8 subnets and 14 hosts per subnet

Correct answer: B

Explanation

A /28 subnet mask uses 4 subnet bits from a default Class C (/24) network, resulting in 2^4 = 16 possible subnets. With 4 bits remaining for hosts (32 - 28 = 4), each subnet can support 2^4 - 2 = 14 usable host addresses after subtracting the network and broadcast addresses. This makes 16 subnets and 14 hosts the correct calculation.