CompTIA Network+ (N10-009) — Question 22

A customer needs six usable IP addresses. Which of the following best meets this requirement?

Answer options

• A. 255.255.255.128
• B. 255.255.255.192
• C. 255.255.255.224
• 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, 14 of which are usable after accounting for the network and broadcast addresses. The other options provide fewer usable addresses; A offers 126, B offers 62, and C offers 30 usable addresses, which do not meet the requirement of six usable IPs.