realjoshbyrnes / fcrdns

NodeJS Forward-confirmed reverse DNS

FCrDNS

NodeJS Forward-confirmed reverse DNS by Joshua Davison

What is it?

FCrDNS will check the PTR records of an IP address, and will check that there is a valid A/AAAA name entry pointing back to the DNS.

In simpler terms, it checks the hostname of the IP address, and the IP address of the hostname match.

Installation

npm install --save fcrdns

Usage:

Usage is simple, and often best shown in code...

var FCrDNS = require('fcrdns'),
    rDNS = new FCrDNS();

rDNS.get('8.8.8.8', function(hostname) {
  if (hostname === null)
    console.log('Unable to verify Google DNS hostname.');
  else
    console.log('The hostname for Google DNS is ' + hostname);
});

FCrDNS(config)

• config <object> (not yet implemented)
  • ttl <number>

FCrDNS.get(address, callback)

• address <string>
• callback <Function>
  • hostname <string>
  • cached <Boolean>

Note that hostname will be null if verification failed, or if there was an error.