CompTIA Network+ (N10-009) — Question 384

A network administrator is configuring a subnet that needs to support 13 usable IP addresses. Which of the following subnet masks best meets this requirement?

Answer options

• A. 255.255.255.128
• B. 255.255.256.192
• C. 255.285.256.224
• D. 255.255.255.240

Correct answer: D

Explanation

The correct answer is D, as a subnet mask of 255.255.255.240 allows for 16 total IP addresses, providing 14 usable addresses after accounting for the network and broadcast addresses. Option A provides only 126 usable addresses, which is excessive for the requirement, while options B and C contain invalid subnet masks and are therefore not applicable.