不悔，谢谢你啦 嘿嘿
找到解决方法了，贴出来，共享下
public class ComputerAddressInfo
    {
        //ComputerAddressInfo cai = new ComputerAddressInfo("10.25.17",42,53);
         
        private int startIP = 0;
 
        private int endIP = 0;
 
        private string ipPrefix = "";
 
        private ArrayList computerList = null;
 
        public ComputerAddressInfo(string ipPrefix,int startIP,int endIP)
        {
 
            this.startIP = startIP;
 
            this.endIP = endIP;
 
            this.ipPrefix = ipPrefix;
 
            computerList = new ArrayList();
        }
 
        public void ScanComputers()
        {
            for(int i=startIP;i<=endIP;i++)
            {
 
                string scanIP = ipPrefix +"."+i.ToString();
 
                IPAddress myScanIP = IPAddress.Parse(scanIP);
 
                IPHostEntry myScanHost = null;
 
                string[] arr = new string[2];
 
                try
                {
                    myScanHost = Dns.GetHostByAddress(myScanIP);
                }
                catch
                {
                    continue;
                }
 
                if (myScanHost != null)
                {
                    arr[0] = myScanHost.HostName;
 
                    arr[1] = scanIP;
                    Console.WriteLine(arr[0]+"       "+arr[1]);
 
                    computerList.Add(arr);
                }
                 
 
            }
 
        }
 
    }

兄弟，可以不可以实现全网检测那些IP地址段的IP在使用和未使用的IP，并获取其使用IP终端的MAC地址？