100-150 Question 76
Single answerA network administrator is tasked with dividing the 192.168.10.0/24 network into smaller subnets to accommodate four departments, each requiring at most 50 devices. Using subnetting, what would be the appropriate subnet mask and the total number of subnets created?
- A
Subnet mask: 255.255.255.192 (/26), Total subnets: 4
- B
Subnet mask: 255.255.255.224 (/27), Total subnets: 8
- C
Subnet mask: 255.255.255.240 (/28), Total subnets: 16
- D
Subnet mask: 255.255.255.128 (/25), Total subnets: 2
Show answer and explanation
Correct answer: A
Explanation
In subnetting, the subnet mask determines the number of subnets and the number of usable IP addresses in each subnet. To accommodate 50 devices per department, each subnet must have at least 50 usable IP addresses. A /26 subnet mask (255.255.255.192) creates 4 subnets, each with 64 total IP addresses and 62 usable IP addresses (after accounting for the network and broadcast addresses), which fits the requirement perfectly.
- A. Correct.
Correct: A /26 subnet mask (255.255.255.192) creates 4 subnets, each supporting up to 62 usable IP addresses, which is sufficient for the requirement of 50 devices per department.
- B. Incorrect.
Incorrect: A /27 subnet mask (255.255.255.224) creates 8 subnets, but each supports only 30 usable IP addresses, which is insufficient for the requirement of 50 devices per department.
- C. Incorrect.
Incorrect: A /28 subnet mask (255.255.255.240) creates 16 subnets, but each supports only 14 usable IP addresses, which is far below the requirement of 50 devices per department.
- D. Incorrect.
Incorrect: A /25 subnet mask (255.255.255.128) creates only 2 subnets, each supporting up to 126 usable IP addresses, but it does not meet the requirement of creating at least 4 subnets for the departments.