using System;
using System.Net;
using System.Net.Sockets;
public class TestNet
{
	public static void Main()
	{
		IPEndPoint ep=new IPEndPoint(IPAddress.Loopback,80);
		Socket s=new Socket(
							AddressFamily.InterNetwork,
							SocketType.Stream, 
							ProtocolType.Tcp);
		s.Connect(ep);
		s.Close();
	}
}