How to get client MAC address in ASP.NET?

 In this article I will explain how to get the client MAC address in ASP.NET using C#.NET.

We may have a requirement to get Client MAC address. We implemented the blow code for Client MAC address.

Add below namespaces to your aspx.cs page.

using System.Net;

using System.Runtime.InteropServices;

using System.Net.NetworkInformation;

public partial class _Default : Page

{

    [DllImport("Iphlpapi.dll")]

    private static extern int SendARP(Int32 dest, Int32 host, ref Int64 mac, ref Int32 length);

    [DllImport("Ws2_32.dll")]

    private static extern Int32 inet_addr(string ip);

In the Page_Load event method add in the following code:

    protected void Page_Load(object sender, EventArgs e)

    {

        try

        {

            string userip = Request.UserHostAddress;

            string strClientIP = Request.UserHostAddress.ToString().Trim();

            Int32 ldest = inet_addr(strClientIP);

            Int32 lhost = inet_addr("");

            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");

            }

            string mac_dest = "";

            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));

                    }

                }

            }

            Response.Write(MAC address is" + mac_dest + "."

             + "<br>");

        }

        catch (Exception err)

        {

            Response.Write(err.Message);

        }

    }

}