how to get macadress of client machine using c# asp.net?

check this previous question and answers: how to get client mac address[^]

You need to import the System.Net namespace in your code for this to work. This will support IPv4 and IPv6.

public string GetMACAddress()
{
NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
String sMacAddress = string.Empty;
foreach (NetworkInterface adapter in nics)
{
if (sMacAddress == String.Empty)// only return MAC Address from first card
{
IPInterfaceProperties properties = adapter.GetIPProperties();
sMacAddress = adapter.GetPhysicalAddress().ToString();
}
} return sMacAddress;
}

To get the client MAC address only way we can rely on JavaScript and Active X control of Microsoft.It is only work in IE if Active X enable for IE. As the ActiveXObject is not available with the Firefox, its not working with the firefox and is working fine in IE.

This script is for IE only:

<script language="javascript" type="text/javascript">
    function showMacAddress() {
        var obj = new ActiveXObject("WbemScripting.SWbemLocator");
        var s = obj.ConnectServer(".");
        var properties = s.ExecQuery("SELECT * FROM Win32_NetworkAdapterConfiguration");
        var e = new Enumerator(properties);
        var output;
        output = '<table border="0" cellPadding="5px" cellSpacing="1px" bgColor="#CCCCCC">';
        output = output + '<tr bgColor="#EAEAEA"><td>Caption</td><td>MACAddress</td></tr>';
        while (!e.atEnd()) {
            e.moveNext();
            var p = e.item();
            if (!p) continue;
            output = output + '<tr bgColor="#FFFFFF">';
            output = output + '<td>' + p.Caption; +'</td>';
            output = output + '<td>' + p.MACAddress + '</td>';
            output = output + '</tr>';
        }
        output = output + '</table>';
        document.getElementById("box").innerHTML = output;
    }
</script>