Check IP

$_SERVER['REMOTE_ADDR'] =
2600:1f28:365:80b0:6254:d19a:12c4:4b

$_SERVER['HTTP_X_FORWARDED_FOR'] =
2600:1f28:365:80b0:6254:d19a:12c4:4b

Check IP service (use with for example pfSense DDNS)