private static string GetClientMAC()        {            string mac_dest = string.Empty;            try            {                string strClientIP = HttpContext.Current.Request.UserHostAddress.ToString().Trim();                Int32 ldest = inet_addr(strClientIP); //目的地的ip                 Int32 lhost = inet_addr("");   //本地服务器的ip                 Int64 macinfo = new Int64();                Int32 len = 6;                int res = SendARP(ldest, 0, ref macinfo, ref len);                string mac_src = macinfo.ToString("X");                while (mac_src.Length < 12)                {                    mac_src = mac_src.Insert(0, "0");                }                for (int i = 0; i < 11; i++)                {                    if (0 == (i % 2))                    {                        if (i == 10)                        {                            mac_dest = mac_dest.Insert(0, mac_src.Substring(i, 2));                        }                        else                        {                            mac_dest = "-" + mac_dest.Insert(0, mac_src.Substring(i, 2));                        }                    }                }            }            catch (Exception ex)            {                Log.Error("GetClientMAC", ex);                //throw ex;            }            return mac_dest;        }

 

上面的代码只能在局域网中使用，在广域网中是拿不到mac的（00-00-00-00-00-00），而且运行时间较长。