Node.JS module for getting ASN for a given IP address. It uses data from http://thyme.apnic.net/current/ .
Mostly inspired by https://www.npmjs.com/package/iptoasn but without native code and using async/await instead of callback style.
npm install --save asnlookup
This module downloads raw BGP table (~13MB) and ASN to name mapping (~2MB) files from http://thyme.apnic.net/current/ and converts them into a more useful format that allows for a quick search.
WARNING: To improve the lookup speed by a lot only /16 at most is currently supported as the first 2 bytes of the address is used for quick lookup! On the upside this makes it more specific for ranges covered by various ASNs
'use strict';
// you must pass a filepath for the local cache, otherwise .asnlookup.cache will be used
const asnlookup = require('./index.js')('.asnlookup.cache');
(async function() {
const testArray = [
'8.8.8.8',
'50.22.180.100',
'1.2.3.4',
'104.16.181.15',
'127.0.0.1',
'asd'
];
// call .load() for an attempt to load the local cache, this will require 10s of MB of memory!
await asnlookup.load();
// check when the cache was updated
// lastUpdated are days
// lastUpdated is Infinity if there's no cache at all
const lastUpdated = asnlookup.lastUpdated();
console.log(`Last updated ${lastUpdated} days ago.`);
// update the cache if it's older than 31 days
if (lastUpdated > 31) {
console.log('Cache too old or never created. Updating...');
await asnlookup.update();
}
testArray.forEach(function(ip) {
console.log(ip, '-', asnlookup.lookup(ip));
});
})();Result of this sample script:
Last updated 0 days ago.
8.8.8.8 - LEVEL3
50.22.180.100 - SOFTLAYER
1.2.3.4 - null
104.16.181.15 - CLOUDFLARENET
127.0.0.1 - null
asd - null