/24 Subnet (255.255.255.0)

The /24 Subnet Explained

A /24 subnet is one of the most widely used subnet sizes in networking. The "/24" in CIDR notation means that the first 24 bits of the IP address are dedicated to the network portion, leaving the remaining 8 bits for host addresses.

Key Details

• Subnet Mask: 255.255.255.0
• Total Addresses: 256 (2^8)
• Usable Host Addresses: 254
• Network Address: The first address (e.g., 192.168.1.0)
• Broadcast Address: The last address (e.g., 192.168.1.255)

How It Works

In the IP address 192.168.1.0/24, the first three octets (192.168.1) identify the network, while the last octet (0-255) identifies individual hosts. The network address (192.168.1.0) and broadcast address (192.168.1.255) are reserved, so usable host IPs range from 192.168.1.1 to 192.168.1.254.

Binary Breakdown

The subnet mask in binary is:

11111111.11111111.11111111.00000000

Each "1" represents a network bit, and each "0" represents a host bit. With 8 host bits, you get 2^8 = 256 total addresses.

Why /24 Is So Popular

The /24 subnet is the default for most home routers and small office networks. It provides enough addresses for typical environments without wasting IP space. It also aligns perfectly with an octet boundary, making it easy to read and calculate mentally.

Subnetting a /24 Further

You can divide a /24 into smaller subnets. For example, splitting into two /25 subnets gives you two networks of 126 usable hosts each. This is useful when you need to segment traffic between departments or VLANs on the same physical infrastructure.