gateway.php

<?php

if (!defined(CURLOPT_RESOLVE)) {
    define('CURLOPT_RESOLVE', 10203);
}

$gateway_port = '443';
$gateway_ip = '140.211.10.16';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://drupal.org/');
curl_setopt($ch, CURLOPT_RESOLVE, array('drupal.org:' . $gateway_port . ':' . $gateway_ip));
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE); 
curl_setopt($ch, CURLOPT_VERBOSE, TRUE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
$result = curl_exec($ch);