ipifytag.js

<script>
  (function () {
    var ip, newNode, referenceNode;

    // helper function to execute once we have the IP address
    function useIP (ip) {
         if (ip.indexOf("194.176.105.") === 0) {
            var el = document.getElementsByTagName('body')[0];
            el.setAttribute('data-n3', 'true');
        }
    }

    if (sessionStorage) {
      ip = sessionStorage.getItem("ipify.ip");
    }
    if (ip) {

      // use IP address retrieved from session cache
      useIP(ip);

    } else {

      // use ipify.org to get IP address
      // listen for when the IP address has been loaded by ipfiy
      window.ipifyCallback = function ipifyCallback (json) {

        if (sessionStorage) {
          sessionStorage.setItem("ipify.ip", json.ip);
        }
        useIP(json.ip);
      };

      // inject the script from ipify.org
      newNode = document.createElement("script");
      newNode.async = true;
      newNode.src = "https://api.ipify.org?format=jsonp&callback=ipifyCallback";
      referenceNode = document.getElementsByTagName("script")[0];
      referenceNode.parentNode.insertBefore(newNode, referenceNode);
    }

  }());
</script>