ip2location: get all ip(s) belonged to a domain - php

Question

I want to have all ip(s) belonged to a domain, e.g. google.com, I recently have a look at this, https://github.com/ip2location/ip2location-cakephp. So, what I am going to do is likes this:
<?php
// clientIp() will iterate from 1.1.1.1 to 255.255.255.255
App::uses('IP2LocationCore', 'IP2Location.Model');
$IP2Location = new IP2LocationCore();
$record = $IP2Location->get($this->request->clientIp());
if(strcmp($record->domainName, 'google.com')) {
// log the ip to a text file
}
?>
My question is: is this solution feasible?, and anyway better than this?

Answer 1

I'm not much of a PHP person, so consider that in my reply!
It seems that what ip2location does is to take an IP address, and gives you its location. It does this (I imagine) by compiling information from assorted data sources.
However you need to start with an IP Address and it will give you the reverse domain that is associated with that. This could well be different than the forward look up address.
For instance I have a hostname vm.example.com that I use to point to a remote desktop session on Azure. If you did a reverse lookup on that address you would not get any information on my domain, you would get the Azure domain, because that's where the reverse is registered.
and as far as I'm aware, unless zone transfers are enabled, there is no way to get all of the hostnames in a domain. At least not without incrementing through the entire domain.
Is there a specific reason you want to do this?

Answer 2

Try using the PHP function gethostbynamel.
<?php
$hosts = gethostbynamel('google.com');
print_r($hosts);
?>
This will for example return:
Array
(
[0] => 173.194.113.35
[1] => 173.194.113.41
[2] => 173.194.113.46
[3] => 173.194.113.34
[4] => 173.194.113.40
[5] => 173.194.113.39
[6] => 173.194.113.33
[7] => 173.194.113.37
[8] => 173.194.113.32
[9] => 173.194.113.38
[10] => 173.194.113.36
)