C#

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

public class GetSocket
{
    private static Socket ConnectSocket(string server, int port)
    {
        Socket s = null;
        IPHostEntry hostEntry = null;

        // Get host related information.
        hostEntry = Dns.GetHostEntry(server);

        // Loop through the AddressList to obtain the supported AddressFamily. This is to avoid
        // an exception that occurs when the host IP Address is not compatible with the address family
        // (typical in the IPv6 case).
        foreach(IPAddress address in hostEntry.AddressList)
        {
            IPEndPoint ipe = new IPEndPoint(address, port);
            Socket tempSocket = 
                new Socket(ipe.AddressFamily, SocketType.Stream, ProtocolType.Tcp);

            tempSocket.Connect(ipe);//HERE IS THE PROBLEM

if(tempSocket.Connected)
            {
                s = tempSocket;
                break;
            }
            else
            {
                continue;
            }
        }
        return s;
    }

    // This method requests the home page content for the specified server.
    private static string SocketSendReceive(string server, int port) 
    {
        string request = "GET / HTTP/1.1\r\nHost: " + server + 
            "\r\nConnection: Close\r\n\r\n";
        Byte[] bytesSent = Encoding.ASCII.GetBytes(request);
        Byte[] bytesReceived = new Byte[256];

        // Create a socket connection with the specified server and port.
        Socket s = ConnectSocket(server, port);

        if (s == null)
            return ("Connection failed");

        // Send request to the server.
        s.Send(bytesSent, bytesSent.Length, 0);  

        // Receive the server home page content.
        int bytes = 0;
        string page = "Default HTML page on " + server + ":\r\n";

        // The following will block until te page is transmitted.
        do {
            bytes = s.Receive(bytesReceived, bytesReceived.Length, 0);
            page = page + Encoding.ASCII.GetString(bytesReceived, 0, bytes);
        }
        while (bytes > 0);

        return page;
    }

    public static void Main(string[] args) 
    {
        string host;
        int port = 80;

        if (args.Length == 0)
            // If no server name is passed as argument to this program, 
            // use the current host name as the default.
            host = Dns.GetHostName();
        else
            host = args[0];

        string result = SocketSendReceive(host, port); 
        Console.WriteLine(result);
        Console.Read();

    }
}

Richard MacCutchan wrote:

btw this is really a TCP/IP issue and not C#.

Richard MacCutchan wrote:

I have no port 80 listener on that system either.

C:\>dir /s /b "c:\windows\microsoft.net\framework\csc.exe
c:\windows\microsoft.net\framework\v1.1.4322\csc.exe
c:\windows\microsoft.net\framework\v2.0.50727\csc.exe
c:\windows\microsoft.net\framework\v3.5\csc.exe
 
C:\>

C:\>c:\windows\microsoft.net\framework\v3.5\csc.exe Hello.cs
Microsoft (R) Visual C# 2008 Compiler version 3.5.30729.1
for Microsoft (R) .NET Framework version 3.5
Copyright (C) Microsoft Corporation. All rights reserved.

C:\>

C:\>hello
Hello, world!

C:\>

C:\>type csc.bat
@c:\windows\microsoft.net\framework\v3.5\csc.exe %*

C:\>