kartik\helpers\Enum::userIP PHP Method

    public static function userIP($filterLocal = true)
    {
        $ipSources = ['HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED', 'REMOTE_ADDR'];
        foreach ($ipSources as $key) {
            if (array_key_exists($key, $_SERVER) === true) {
                foreach (array_map('trim', explode(',', $_SERVER[$key])) as $ip) {
                    if ($filterLocal) {
                        $checkFilter = filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE);
                        if ($checkFilter !== false) {
                            return $ip;
                        }
                    } else {
                        return $ip;
                    }
                }
            }
        }
        return 'Unknown';
    }