cidr-js

Node module for for expanding cidr blocks in a list of IP (a-z) or just the range (start & end)

Install

npm install cidr-js

Example Usage

Get just the start and end IPs

var CIDR = require("cidr-js");
var cidr = new CIDR();

var block = "127.0.0.0/31";
var results = cidr.range(block);

// should return ['127.0.0.0', '127.0.0.1']

Get a list of ips in a given range

var CIDR = require("cidr-js");
var cidr = new CIDR();
var block = "127.0.0.0/30";
var results = cidr.list(block);

// should return [ '127.0.0.0', '127.0.0.1', '127.0.0.2', '127.0.0.3' ]

Filter a list of ips into contiguous blocks

var ips = [
    // contiguous block
    '127.0.0.0',
    '127.0.0.1',
    '127.0.0.2',
    '127.0.0.3',
    '127.0.0.4',
    '127.0.0.5',
    '127.0.0.6',

    // new contiguous block
    '127.0.1.1',
    '127.0.1.2',
    '127.0.1.3',

    // dangling block
    '127.0.1.5'
];

var CIDR = require('cidr-js');
var cidr = new CIDR();
var results = cidr.filter(ips);

// should return
{
  '12700': [
    '127.0.0.1',
    '127.0.0.2',
    '127.0.0.3',
    '127.0.0.4',
    '127.0.0.5',
    '127.0.0.6'
  ],
  '12701': [
    '127.0.1.1',
    '127.0.1.2',
    '127.0.1.3'
  ],
  '127015': [
    '127.0.1.5'
  ]
}

Get IP blocks from a list of IPs

var ips = [
    // contiguous block
    "127.0.0.0",
    "127.0.0.1",
    "127.0.0.2",
    "127.0.0.3",
    "127.0.0.4",
    "127.0.0.5",
    "127.0.0.6",

    // new contiguous block
    "127.0.1.1",
    "127.0.1.2",
    "127.0.1.3",

    // dangling block
    "127.0.1.5",
];
var CIDR = require("cidr-js");
var cidr = new CIDR();
var results = cidr.getBlocks(ips);

// should return
[
    "127.0.0.0/30",
    "127.0.0.4/31",
    "127.0.0.6/32",
    "127.0.1.1/32",
    "127.0.1.2/31",
    "127.0.1.5",
];