TCP 端口检测

try
   {
     IPHostEntry host = Dns.GetHostEntry(address);
     IPAddress ip = host.AddressList[0];
      IPEndPoint point = new IPEndPoint(ip, port);
      Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
      sock.Connect(point);
      Console.WriteLine("连接TCP端口{0}成功！", point);
   }
catch (SocketException e)
   {
       Console.WriteLine("连接TCP端口{0}失败！", point);
   }

udp 端口检测

try
   {
      var ntpData = new byte[48];
      ntpData[0] = 11;
      var addresses = Dns.GetHostEntry(address);
      IPAddress ip = addresses.AddressList[0];
      var ipEndPoint = new IPEndPoint(ip, port);
      var socket = new Socket(AddressFamily.InterNetwork,      SocketType.Dgram, ProtocolType.Udp);
      socket.Connect(ipEndPoint);
      socket.ReceiveTimeout = 3000;
      socket.Send(ntpData);
      socket.Receive(ntpData);
      socket.Close();
      Console.WriteLine("连接UDP端口{0}成功！", point);        
    }
      catch
    {
      Console.WriteLine("连接UDP端口{0}失败！", point);                        
    }