CompTIA Network+ (N10-009) — Question 123

A network administrator needs to add 255 useable IP addresses to the network. A /24 is currently in use. Which of the following prefixes would fulfill this need?

Answer options

• A. /23
• B. /25
• C. /29
• D. /32

Correct answer: A

Explanation

The /23 prefix offers 510 usable IP addresses, which satisfies the need for 255 addresses. The /25 prefix only provides 126 usable addresses, while /29 and /32 offer far fewer, making them inadequate for this requirement.