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    static class MacAddressProvider

    {

        const int PING_TIMEOUT = 1000;

        [DllImport("iphlpapi.dll", ExactSpelling = true)]

        static extern int SendARP(int DestIP, int SrcIP, byte[] pMacAddr, ref uint PhyAddrLen);

        // *********************************************************************

        /// <summary>

        /// Gets the MAC address from ARP table in colon (:) separated format.

        /// </summary>

        /// <param name="hostNameOrAddress">Host name or IP address of the

        /// remote host for which MAC address is desired.</param>

        /// <returns>A string containing MAC address; null if MAC address could

        /// not be found.</returns>

        public  static string GetMACAddressFromARP(string hostNameOrAddress)

        {

            if (!IsHostAccessible(hostNameOrAddress))

                return null;

            IPHostEntry hostEntry = Dns.GetHostEntry(hostNameOrAddress);

            if (hostEntry.AddressList.Length == 0)

                return null;   

            byte[] macAddr = new byte[6];

            uint macAddrLen = (uint)macAddr.Length;

            if (SendARP((int)hostEntry.AddressList[0].Address, 0, macAddr, ref macAddrLen) != 0)

                return null;

            StringBuilder macAddressString = new StringBuilder();

            for (int i = 0; i < macAddr.Length; i++)

            {

                if (macAddressString.Length > 0)

                    macAddressString.Append(":");

                macAddressString.AppendFormat("{0:x2}", macAddr[i]);

            }

            return macAddressString.ToString();

        }

        // *********************************************************************

        /// <summary>

        /// Checks to see if the host specified by

        /// <paramref name="hostNameOrAddress"/> is currently accessible.

        /// </summary>

        /// <param name="hostNameOrAddress">Host name or IP address of the

        /// remote host for which MAC address is desired.</param>

        /// <returns><see langword="true" /> if the host is currently accessible;

        /// <see langword="false"/> otherwise.</returns>

        private static bool IsHostAccessible(string hostNameOrAddress)

        {

            Ping ping = new Ping();

            PingReply reply = ping.Send(hostNameOrAddress, PING_TIMEOUT);

            return reply.Status == IPStatus.Success;

        }

    }