C#擷取區域網路ip段

      static void Main()
        {          
            ArrayList list = GetAllLocalMachines();
for (int i = 0; i < list.Count; i++)
            {
                Console.WriteLine(list[i]);
            }          
            Console.ReadKey();
        }

 //首先來個迴圈ping一下那個網段的主機。
//其次用以下的函數去擷取所有的區域網路內有響應的ip地址清單
        public static ArrayList GetAllLocalMachines()
        {
            Process p = new Process();
            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.CreateNoWindow = true;
            p.Start(); p.StandardInput.WriteLine("arp -a");
            p.StandardInput.WriteLine("exit");
            ArrayList list = new ArrayList();
            StreamReader reader = p.StandardOutput;//讀取ip。mac。。。。
            string IPHead = Dns.GetHostByName(Dns.GetHostName()).AddressList[0].ToString().Substring(0, 3);
for (string line = reader.ReadLine(); line != null; line = reader.ReadLine())
            {
                line = line.Trim(); if (line.StartsWith(IPHead) && (line.IndexOf("動態") != -1))
                {
string IP = line.Substring(0, 15).Trim(); string Mac = line.Substring(line.IndexOf("-") - 2, 0x11).Trim();

                    list.Add(IP);
                }
            }
return list;
        }