ip-range-check

Check whether an IP(v4 or v6) is in an CIDR range

Usage no npm install needed!

<script type="module">
  import ipRangeCheck from 'https://cdn.skypack.dev/ip-range-check';
</script>

README

IP Range Check

Build Status

NPM

This module lets you check if an IP matches one or more IP's or CIDR ranges. It handles IPv6, IPv4, and IPv4-mapped over IPv6 addresses.

It accepts either:

  • A single CIDR or IP string, e.g. "125.19.23.0/24", or "2001:cdba::3257:9652", or "62.230.58.1"
  • An array of CIDR and/or IP strings, e.g. ["125.19.23.0/24", "2001:cdba::3257:9652", "62.230.58.1"]

Importantly, it cannot match an IPv4 address to an IPv6 CIDR or vice versa, (IPv4-mapped IPv6 addresses notwithstanding).

Installing

npm install ip-range-check --save

IPv4

var ipRangeCheck = require("ip-range-check");

// Checks CIDR
ipRangeCheck("192.168.1.1", "102.1.5.2/24")
// > false
ipRangeCheck("192.168.1.1", "192.168.1.0/24")
// > true

// Checks if IP matches string
ipRangeCheck("192.168.1.1", "192.168.1.1")
// > true

// Checks array of CIDR's and string
ipRangeCheck("192.168.1.1", ["102.1.5.2/24", "192.168.1.0/24", "106.1.180.84"])
// > true

// Compare IPv6 with IPv4
ipRangeCheck("195.58.1.62", ["::1/128", "125.92.12.53"])
// > false

IPv6

var ipRangeCheck = require("ip-range-check");

// Handles IPv6 in the same fashion as IPv4
ipRangeCheck("::1", "::2/128")
// > false
ipRangeCheck("::1", ["::2", "::3/128"])
// > false
ipRangeCheck("2001:cdba::3257:9652", "2001:cdba::3257:9652/128")
// > true

// IPv4-mapped IPv6 addresses are automatically converted back to IPv4 addresses
// and will match against IPv4 CIDR/IP's.
ipRangeCheck("0:0:0:0:0:FFFF:222.1.41.90", "222.1.41.0/24")
// > true

// IPv6 addresses/CIDR's are normalised
ipRangeCheck("2001:cdba:0000:0000:0000:0000:3257:9652", ["2001:cdba::3257:9652"])
// > true

Developing

To run the tests:

npm test