IP MASTER
Advanced Subnet Calculator
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Simplify Your Network Planning
Whether you are a network engineer planning a data center or a student studying for the CCNA, understanding subnetting is crucial. Subnetting breaks a large network into smaller, more manageable pieces.
This tool not only calculates your subnet mask and range but allows you to export the data to Excel for your documentation.
IPv4 Subnet Calculator
IPv6 Subnet Calculator
IPv4 Supernet Divider
Break a large network (Supernet) into smaller subnets and export the list.
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Common Questions
What is a Subnet Mask?
A subnet mask is a 32-bit number that masks an IP address, and divides the IP address into network address and host address.
Why use CIDR notation?
CIDR (Classless Inter-Domain Routing) allows for more flexible allocation of IP addresses than the original class system. A notation like `/24` is much quicker to write than `255.255.255.0`.
How many hosts are in a /30 subnet?
A /30 subnet has 4 total addresses, but only 2 are usable for hosts. One is the network address, and one is the broadcast address. It is typically used for point-to-point links.
What is IPv6 and how does it work?
IPv6 (Internet Protocol version 6) is the successor to IPv4, designed to solve address exhaustion. It works using 128-bit addresses, providing approximately 3.4 × 10³⁸ unique IP addresses. This allows for more efficient routing and simpler network configuration without the need for NAT.
How is IPv6 different from IPv4?
The primary difference is address size: IPv4 is 32-bit (numeric, e.g., 192.168.1.1) while IPv6 is 128-bit (hexadecimal, e.g., 2001:db8::1).
IPv6 also offers built-in security features, more efficient packet headers, and better support for mobile devices compared to IPv4.
IPv6 also offers built-in security features, more efficient packet headers, and better support for mobile devices compared to IPv4.
Visual Subnetting Tree (Splitting /16)
This tree demonstrates how a large /16 Supernet breaks down. Every time you increase the CIDR by 1, you double the number of subnets but halve the number of IPs.
/16 Supernet (65,536 IPs) │ ├── /17 Subnet A (32,768 IPs) │ │ │ ├── /18 Subnet A1 (16,384 IPs) │ │ │ │ │ ├── /19 Subnet (8,192 IPs) │ │ │ │ │ │ │ ├── /20 ... │ │ │ │ └── ... -> /24 (256 IPs) │ │ │ └── /20 ... │ │ └── /19 ... │ └── 18 ... └── /17 Subnet B (32,768 IPs) ...