Parse and lookup IP network blocks
The Netmask class parses and understands IPv4 CIDR blocks so they can be explored and compared. This module is highly inspired by Perl Net::Netmask module.
var Netmask = require('netmask').Netmask var block = new Netmask('10.0.0.0/12'); block.base; // 10.0.0.0 block.mask; // 255.240.0.0 block.bitmask; // 12 block.hostmask; // 0.15.255.255 block.broadcast; // 10.15.255.255 block.size; // 1048576 block.first; // 10.0.0.1 block.last; // 10.0.255.254 block.contains('10.0.8.10'); // true block.contains('10.8.0.10'); // false block.contains('192.168.1.20'); // false block.forEach(function(ip, long, index)); block.next() // Netmask('10.16.0.0/12')
Netmask objects are created with an IP address and optionally a mask. There are many forms that are recognized:
'188.8.131.52/24' // The preferred form. '184.108.40.206/255.255.255.0' '220.127.116.11', '255.255.255.0' '18.104.22.168', 0xffffff00 '22.214.171.124' // A /32 block. '216.240.32' // A /24 block. '216.240' // A /16 block. '140' // A /8 block. '216.240.32/24' '216.240/16'
.base: The base address of the network block as a string (eg: 126.96.36.199). Base does not give an indication of the size of the network block.
.mask: The netmask as a string (eg: 255.255.255.0).
.hostmask: The host mask which is the opposite of the netmask (eg: 0.0.0.255).
.bitmask: The netmask as a number of bits in the network portion of the address for this block (eg: 24).
.size: The number of IP addresses in a block (eg: 256).
.broadcast: The blocks broadcast address (eg: 192.168.1.0/24 => 192.168.1.255)
.last: First and last useable address
.contains(ip or block): Returns a true if the IP number
ipis part of the network. That is, a true value is returned if
broadcast. If a Netmask object or a block is given, it returns true only of the given block fits inside the network.
.forEach(fn): Similar to the Array prototype method. It loops through all the useable addresses, ie between
.next(count): Without a
count, return the next block of the same size after the current one. With a count, return the Nth block after the current one. A count of -1 returns the previous block. Undef will be returned if out of legal address space.
.toString(): The netmask in base/bitmask format (e.g., '188.8.131.52/24')
$ npm install netmask
(The MIT License)
Copyright (c) 2011 Olivier Poitrey firstname.lastname@example.org
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