foreach(String o in Request.ServerVariables){
    Response.Write(o+"="+Request.ServerVariables[o]+"<br>");
}

string stringMAC = "";
   string stringIP = "";
   ManagementClass MC = new ManagementClass ("Win32_NetworkAdapterConfiguration");
   ManagementObjectCollection MOC= MC.GetInstances();

   foreach(ManagementObject MO in MOC)
   {
    if ((bool)MO["IPEnabled"] == true)
    {
       stringMAC += MO["MACAddress"].ToString(); //获取网卡的地址
       string[] IPAddresses = (string[]) MO["IPAddress"]; //获取本地的IP地址
       if(IPAddresses.Length > 0)
       stringIP = IPAddresses[0];
       Response.Write(stringMAC+"/"+stringIP);
     }
   }

//要引用到以下两个命名空间
using System.Diagnostics;
using System.Text.RegularExpressions;

//获取远程客户端的网卡物理地址（MAC）
public string GetMac(string IP)   //para IP is the client's IP
{
string dirResults="";
ProcessStartInfo psi = new ProcessStartInfo();
Process proc = new Process();
psi.FileName = "nbtstat";
psi.RedirectStandardInput = false;
psi.RedirectStandardOutput = true;
psi.Arguments = "-A " + IP;
psi.UseShellExecute = false;
proc = Process.Start(psi);
dirResults = proc.StandardOutput.ReadToEnd();
proc.WaitForExit();
dirResults=dirResults.Replace("\r","").Replace("\n","").Replace("\t","");

Regex reg=new Regex("Mac[ ]{0,}Address[ ]{0,}=[ ]{0,}(?<key>((.)*?))__MAC",RegexOptions.IgnoreCase|RegexOptions.Compiled);
Match mc=reg.Match(dirResults+"__MAC");

if(mc.Success)   
{
return mc.Groups["key"].Value;
}
else
{
reg=new Regex("Host not found",RegexOptions.IgnoreCase|RegexOptions.Compiled);
mc=reg.Match(dirResults);
if(mc.Success)
{
return "Host not found!";
}
else
{
return "";
}
}
}

//在页面上打印出客户端的网卡物理地址（MAC）
Response.Write(this.GetMac(Request.UserHostAddress.ToString()));