I had got client's IP address by $REMOTE_ADDR or $_SERVER['REMOTE_ADDR'], but it does not work on latest version of PHP.
Following code helps you to get the correct client IP address.
function get_client_ip_env() { $ipaddress = ''; if (getenv('HTTP_CLIENT_IP')) $ipaddress = getenv('HTTP_CLIENT_IP'); else if(getenv('HTTP_X_FORWARDED_FOR')) $ipaddress = getenv('HTTP_X_FORWARDED_FOR'); else if(getenv('HTTP_X_FORWARDED')) $ipaddress = getenv('HTTP_X_FORWARDED'); else if(getenv('HTTP_FORWARDED_FOR')) $ipaddress = getenv('HTTP_FORWARDED_FOR'); else if(getenv('HTTP_FORWARDED')) $ipaddress = getenv('HTTP_FORWARDED'); else if(getenv('REMOTE_ADDR')) $ipaddress = getenv('REMOTE_ADDR'); else $ipaddress = 'UNKNOWN'; return $ipaddress; }