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N10-009 · Question #53

A network administrator needs to divide 192.168.1.0/24 into two equal halves. Which of the following subnet masks should the administrator use?

The correct answer is D. 255.255.255.128. Understanding Subnetting: Original Network: 192.168.1.0/24 has a subnet mask of 255.255.255.0, which allows for 256 IP addresses (including network and broadcast addresses). Objective: Divide this network into two equal subnets. Calculating Subnet Mask: New Subnet Mask: To…

Submitted by rania.sa· Mar 6, 2026Networking Concepts

Question

A network administrator needs to divide 192.168.1.0/24 into two equal halves. Which of the following subnet masks should the administrator use?

Options

  • A255.255.0.0
  • B255.255.254.0
  • C255.255.255.0
  • D255.255.255.128

How the community answered

(25 responses)
  • A
    16% (4)
  • B
    4% (1)
  • C
    4% (1)
  • D
    76% (19)

Explanation

Understanding Subnetting: Original Network: 192.168.1.0/24 has a subnet mask of 255.255.255.0, which allows for 256 IP addresses (including network and broadcast addresses). Objective: Divide this network into two equal subnets. Calculating Subnet Mask: New Subnet Mask: To divide 192.168.1.0/24 into two equal halves, we need to borrow one bit from the host portion of the address, changing the subnet mask to 255.255.255.128 (/25). Subnet Breakdown: First Subnet: 192.168.1.0/25 (192.168.1.0 - 192.168.1.127) Second Subnet: 192.168.1.128/25 (192.168.1.128 - 192.168.1.255) Each subnet now has 128 IP addresses (126 usable IP addresses, excluding the network and broadcast addresses).

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