200-301 Question 276
Single answerA network administrator is tasked with designing a subnet for an IP address of 192.168.10.0/24. The requirement is to create 4 subnets of equal size. What subnet mask should the administrator use to meet this requirement?
- A
/25
- B
/26
- C
/27
- D
/28
Show answer and explanation
Correct answer: B
Explanation
To create 4 subnets of equal size from a /24 network, the subnet mask must allow for exactly 4 divisions of the original network. A /26 mask achieves this by borrowing 2 bits from the host portion (2^(26-24) = 4 subnets), making it the correct choice.
- A. Incorrect.
/25 creates 2 subnets (2^(25-24) = 2), which is insufficient for the requirement of 4 subnets.
- B. Correct.
/26 creates 4 subnets (2^(26-24) = 4), which meets the requirement.
- C. Incorrect.
/27 creates 8 subnets (2^(27-24) = 8), which exceeds the requirement of 4 subnets. While this is valid, it does not achieve the equal size requirement with the least number of subnets.
- D. Incorrect.
/28 creates 16 subnets (2^(28-24) = 16), which exceeds the requirement. This would waste address space and is not an efficient choice.