MyWebUtils: Free Online Dev Tools

What is Subnetting?

Subnetting is the practice of dividing a single, large computer network into smaller, more manageable sub-networks, or "subnets." It's a fundamental concept in networking that helps improve performance, enhance security, and simplify network management. This calculator focuses on IPv4 subnetting.

Why is This Tool Essential for Network Engineers?

• Efficient IP Address Allocation: Subnetting allows for the logical division of an IP address block, preventing waste and ensuring there are enough addresses for all devices on a network.
• Network Planning and Design: When designing a new network, this calculator helps you determine the correct subnet mask (or CIDR prefix) to meet the required number of hosts per department or location.
• Troubleshooting: Quickly determine if a device is on the correct subnet by calculating its network and broadcast addresses. This helps diagnose routing and connectivity problems.
• Security: By segmenting a network, you can create security boundaries. For example, you can place a public-facing web server on one subnet and a secure internal database on another, with a firewall controlling traffic between them.

How to Use Our Subnet Calculator

This tool instantly provides all the critical information about a given subnet:

• IP Address & CIDR Prefix: Enter an IP address and a CIDR prefix (e.g., /24). The calculator will automatically update as you type.
• Network Information: It instantly calculates the Subnet Mask, Network Address, Broadcast Address, and the range of usable host IP addresses.
• Host Count: See the total number of IP addresses in the subnet and how many are actually available for devices (usable hosts).
• Binary Representation: For educational purposes or deep-level analysis, you can view the binary versions of the IP address and subnet mask.