Package Exports

is-in-subnet

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (is-in-subnet) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

is-in-subnet

Check if an IPv4 or IPv6 address is contained in the given CIDR subnet.

Small
Fast
Simple syntax
Full test coverage
TypeScript-friendly
Zero dependencies

Installation

npm i is-in-subnet

Usage

const { isInSubnet } = require('is-in-subnet');

console.log( isInSubnet('10.5.0.1', '10.4.5.0/16') );   // false
console.log( isInSubnet('10.5.0.1', '10.4.5.0/15') );   // true

console.log( isInSubnet('2001:db8:f53a::1', '2001:db8:f53b::1:1/48') );   // false
console.log( isInSubnet('2001:db8:f53a::1', '2001:db8:f531::1:1/44') );   // true

More ways to use it

Test multiple subnets at once

You can pass an array instead of a single subnet.

const inAnySubnet = isInSubnet('10.5.0.1', [ '10.4.5.0/16', '192.168.1.0/24' ]);

This module recognizes several special classes of addresses.

Private addresses

isPrivate(address);

True if the address is in a private/internal address range, such as 192.168.1.1 or similar, or an IPv6 Unique Local Address.

Localhost addresses

isLocalhost(address);

True if the address represents the localhost, such as 127.0.0.1 or ::1.