求C#获取真实IP地址的方法

public static string GetRealIp()
        {
            string ip="";
            try
            {
                HttpRequest request = HttpContext.Current.Request;

                if (request.ServerVariables["http_VIA"] != null)
                {
                    ip = request.ServerVariables["http_X_FORWARDED_FOR"].ToString().Split(',')[0].Trim();
                }
                else
                {
                    ip = request.UserHostAddress;
                }
            }
            catch (Exception e)
            {
                throw e;
            }

            return ip;
        }