[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);
    public string GetClientMac(string IP)
    {
        string MacAddress = "";//mac地址 例如:"00-13-D4-D5-2F-20"

        try
        {
            Int32 ClientIP = inet_addr(IP); //目的地的ip(客户端Ip的Int32形式:"67152064")           

            Int64 MacInfo = new Int64();//存储mac地址的Int64形式:"35389822997248"

            Int32 Length = 6;

            int res = SendARP(ClientIP, 0, ref MacInfo, ref Length);

            string mac_src = MacInfo.ToString("X");//存储mac地址的16进制形式:"202fd5d41300"

            while (mac_src.Length < 12)
            {
                mac_src = mac_src.Insert(0, "0");//不足12为则用0来填充
            }

            //把Int32形式的IP转换为"00-13-D4-D5-2F-20"形式的mac地址
            for (int i = 0; i < 11; i++)
            {
                if (0 == (i % 2))
                {
                    if (i == 10)
                    {
                        MacAddress = mac_dest.Insert(0, mac_src.Substring(i, 2));
                    }
                    else
                    {
                        MacAddress = "-" + mac_dest.Insert(0, mac_src.Substring(i, 2));
                    }
                }
            }

        }
        catch (Exception err)
        {
            throw err;
        }
        return mac_dest;
    }

------解决方案--------------------
都不太能

现在的状况下，你是不可能在页面上运行
wscript ,更不可能调用wmi

------解决方案--------------------
至于arp的那个，完全是局域网用的，广域网上一点用都没有

------解决方案--------------------
  


如果发送ARP包来查询mac地址的话，基本上会被防火墙屏蔽