note 102793 modified in function.curl-setopt by danbrown

Force Curl Request To Go To A Particular IP Address

Yes, there is a method of passing an IP address to curl.  Excellent for services with multiple IP addresses and also to take DNS out of the equation for testing/debugging.

<?php
    function fetch_page($url, $host_ip = NULL)
    {

      $ch = curl_init();

      if (!is_null($host_ip))
      {
        $urldata = parse_url($url);

        //  Ensure we have the query too, if there is any...
        if (!empty($urldata['query']))
          $urldata['path'] .= "?".$urldata['query'];

        //  Specify the host (name) we want to fetch...
        $headers = array("Host: ".$urldata['host']);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        //  create the connecting url (with the hostname replaced by IP)
        $url = $urldata['scheme']."://".$host_ip.$urldata['path'];
      }

      curl_setopt($ch,  CURLOPT_URL, $url);
      curl_setopt ($ch, CURLOPT_HEADER, 0);
      curl_setopt($ch,  CURLOPT_RETURNTRANSFER, true);

      $result = curl_exec ($ch);
      curl_close ($ch);

      return $result;
    }
?>

--was--
Force Curl Request To Go To A Particular IP Address

Yes, there is a method of passing an IP address to curl.  Excellent for services with multiple IP addresses and also to take DNS out of the equation for testing/debugging.

    function fetch_page($url, $host_ip = NULL)
    {

      $ch = curl_init();

      if (!is_null($host_ip))
      {
        $urldata = parse_url($url);

        //  Ensure we have the query too, if there is any...
        if (!empty($urldata['query']))
          $urldata['path'] .= "?".$urldata['query'];

        //  Specify the host (name) we want to fetch...
        $headers = array("Host: ".$urldata['host']);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        //  create the connecting url (with the hostname replaced by IP)
        $url = $urldata['scheme']."://".$host_ip.$urldata['path'];
      }

      curl_setopt($ch,  CURLOPT_URL, $url);
      curl_setopt ($ch, CURLOPT_HEADER, 0);
      curl_setopt($ch,  CURLOPT_RETURNTRANSFER, true);

      $result = curl_exec ($ch);
      curl_close ($ch);

      return $result;
    }

http://php.net/manual/en/function.curl-setopt.php