获得MAC地址的四个方法

１．使用WMI。查询表Win32_NetworkAdapterConfiguration即可获得。

２．使用ARP协议。请看这里。

３．使用Windows命令nbtstat，也就是通过NetBIOS。请看这里。

４．查询SNMP（就是一种用于监视网络设备的协议）的MIB（管理信息数据库）。但这不是一件简单的事情，需要自己创建SNMP包，发送到交换机，然后对返回的响应进行解析。

下面是代碼：

using System;
using System.Diagnostics;
using System.Management;
using System.Net;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;

namespace MACAddress
{
    /**//// <summary>
    /// MainClass 的摘要描述。
    /// </summary>
    internal class MainClass
    {
        /**//// <summary>
        /// 應用程式的主進入點。
        /// </summary>
        [STAThread]
        private static void Main(string[] args)
        {
            GetMACByWMI();
            IPAddress[] ips = GetLocalIP();
            foreach (IPAddress ip in ips)
            {
                Console.WriteLine(GetMacByARP(ip.ToString()));
                string mac = GetRemoteMacByNetBIOS(ip.ToString());
                if ( mac.Length != 0 )
                    Console.WriteLine(mac);
                else
                    Console.WriteLine("Fail to get MACAddress by NetBIOS");
                GetMACBySNMP(ip.ToString(),"yourGroupName@yourVlanNumber");
            }
            Console.ReadLine();
        }

        By WMI#region By WMI

        public static void GetMACByWMI()
        {
            string query = "select MACAddress from Win32_NetworkAdapterConfiguration where IPEnabled='TRUE'";
            ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
            ManagementObjectCollection collection = searcher.Get();
            foreach (ManagementObject mo in collection)
            {
                string mac = mo["MACAddress"].ToString();
                Console.WriteLine(" Network card MAC Address is :{0}", mac);
            }
        }

        #endregion

        By ARP#region By ARP

        [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 static string GetMacByARP(string clientIP)
        {
            string ip = clientIP;
            Int32 ldest = inet_addr(ip);
            Int64 macinfo = new Int64();
            Int32 len = 6;
            try
            {
                SendARP(ldest, 0, ref macinfo, ref len);
            }
            catch
            {
                return "";
            }
            string originalMACAddress = Convert.ToString(macinfo, 16);
            if (originalMACAddress.Length < 12)
            {
                originalMACAddress = originalMACAddress.PadLeft(12, '0');
            }
            string macAddress;
            if (originalMACAddress != "0000" && originalMACAddress.Length == 12)
            {
                string mac1, mac2, mac3, mac4, mac5, mac6;
                mac1 = originalMACAddress.Substring(10, 2);
                mac2 = originalMACAddress.Substring(8, 2);
                mac3 = originalMACAddress.Substring(6, 2);
                mac4 = originalMACAddress.Substring(4, 2);
                mac5 = originalMACAddress.Substring(2, 2);
                mac6 = originalMACAddress.Substring(0, 2);
                macAddress = mac1 + "-" + mac2 + "-" + mac3 + "-" + mac4 + "-" + mac5 + "-" + mac6;
            }
            else
            {
                macAddress = "";
            }
            return macAddress.ToUpper();
        }

        public static IPAddress[] GetLocalIP()
        {
            string hostName = Dns.GetHostName();
            IPHostEntry ipEntry = Dns.GetHostByName(hostName);
            return ipEntry.AddressList;
        }

        #endregion

        By NetBIOS#region By NetBIOS
        public static string GetRemoteMacByNetBIOS(string clientIP)
        {
            string ip = clientIP;
            string dirResults = "";
            ProcessStartInfo psi = new ProcessStartInfo();
            Process proc = new Process();
            psi.FileName = "nbtstat.exe";
            //psi.RedirectStandardInput = false; 
            psi.RedirectStandardOutput = true;
            psi.RedirectStandardError = true;
            psi.Arguments = "-A " + ip;
            psi.UseShellExecute = false;
            proc = Process.Start(psi);
            dirResults = proc.StandardOutput.ReadToEnd();
            string error = proc.StandardError.ReadToEnd();
            proc.WaitForExit();
            dirResults = dirResults.Replace("\r", "").Replace("\n", "").Replace("\t", "");
            Regex reg = new Regex("Mac[ ]{0,}Address[ ]{0,}=[ ]{0,}(?((.)*?))__MAC", RegexOptions.IgnoreCase | RegexOptions.Compiled);
            Match mc = reg.Match(dirResults + "__MAC");
            if (mc.Success)
            {
                return mc.Groups["key"].Value.ToUpper();
            }
            else
            {
                return "";
            }
        }
        #endregion

        By SNMP#region By SNMP
        public static void GetMACBySNMP(string ip,string vlan)
        {
            int commLength,mibLength,dataStart,dataLength;
            string nextMib,value;
            SNMP conn = new SNMP();
            string mib = "1.3.6.1.2.1.17.4.3.1.1";
            int orgMibLength = mib.Length;
            byte[] response = new byte[1024];

            nextMib = mib;

            while ( true)
            {
                response = conn.Get("getnext",ip,vlan,nextMib);
                commLength = Convert.ToInt16(response[6]);
                mibLength = Convert.ToInt16(response[23+commLength]);
                dataLength = Convert.ToInt16(response[25+commLength+mibLength]);
                dataStart = 26 + commLength + mibLength;
                value = BitConverter.ToString(response,dataStart,dataLength);
                nextMib = conn.GetNextMIB(response);

                if ( !(nextMib.Substring(0,orgMibLength) == mib))
                {
                    break;
                }
                Console.WriteLine("{0}={1}",nextMib,value);

            }
        }
        #endregion
    }
}

SNMP Class

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace MACAddress
{
    /**//**//**//// <summary>
    /// SNMP 的摘要描述。
    /// </summary>
    public class SNMP
    {
        public SNMP()
        {
        }

        public byte[] Get(string request, string host, string community, string mibString)
        {
            byte[] packet = new byte[1024];
            byte[] mib = new byte[1024];
            int snmpLen;
            int comLen = community.Length;
            string[] mibVals = mibString.Split('.');
            int mibLen = mibVals.Length;
            int cnt = 0;
            int temp;
            int orgmibLen = mibLen;
            int pos = 0;
            for (int i = 0; i < orgmibLen; i++)
            {
                temp = Convert.ToInt16(mibVals[i]);
                if (temp > 127)
                {
                    mib[cnt] = Convert.ToByte(128 + (temp / 128));
                    mib[cnt + 1] = Convert.ToByte(temp - ((temp / 128) * 128));
                    cnt += 2;
                    mibLen++;
                }
                else
                {
                    mib[cnt] = Convert.ToByte(temp);
                    cnt++;
                }
            }

            snmpLen = 29 + comLen + mibLen - 1;
            packet[pos++] = 0x30;
            packet[pos++] = Convert.ToByte(snmpLen - 2);

            packet[pos++] = 0x02;
            packet[pos++] = 0x01;
            packet[pos++] = 0x00;

            packet[pos++] = 0x04;
            packet[pos++] = Convert.ToByte(comLen);
            byte[] data = Encoding.ASCII.GetBytes(community);
            for (int i = 0; i < data.Length; i++)
            {
                packet[pos++] = data[i];
            }

            if (request == "get")
            {
                packet[pos++] = 0xA0;
            }
            else
            {
                packet[pos++] = 0xA1;
            }
            packet[pos++] = Convert.ToByte(20 + mibLen - 1);

            packet[pos++] = 0x02;
            packet[pos++] = 0x04;
            packet[pos++] = 0x00;
            packet[pos++] = 0x00;
            packet[pos++] = 0x00;
            packet[pos++] = 0x01;

            packet[pos++] = 0x02;
            packet[pos++] = 0x01;
            packet[pos++] = 0x00;

            packet[pos++] = 0x02;
            packet[pos++] = 0x01;
            packet[pos++] = 0x00;

            packet[pos++] = 0x30;

            packet[pos++] = Convert.ToByte(6 + mibLen - 1);
            packet[pos++] = 0x30;
            packet[pos++] = Convert.ToByte(6 + mibLen - 1 - 2);
            packet[pos++] = 0x06;
            packet[pos++] = Convert.ToByte(mibLen - 1);

            packet[pos++] = 0x2b;
            for (int i = 2; i < mibLen; i++)
            {
                packet[pos++] = Convert.ToByte(mib[i]);
            }
            packet[pos++] = 0x05;