C# Discussion Boards - CodeProject

15-Oct-08 12:37

Hi friends,
I wrote a TcpListener in my machine in port 20000 and clients connect to this server and everything's fine in LAN, but I have error in Internet connections, here's my Listener code:

int port = 20000;
     string recieved = null;
     string send = null;
     TcpListener listener = new TcpListener(IPAddress.Any, port);
     listener.Start();

     TcpClient tcp = listener.AcceptTcpClient();
     NetworkStream netstream = tcp.GetStream();
     StreamReader sr = new StreamReader(netstream);
     StreamWriter sw = new StreamWriter(netstream);

     recieved = sr.ReadLine();
     Console.WriteLine("\nMessage Recieved : " + recieved);

     send = Console.ReadLine();
     sw.WriteLine(send);
     sw.Flush();
     Console.WriteLine("\nMessage Sent : " + send);

     netstream.Close();
     tcp.Close();

and Client code:

string server = "192.168.1.4";
     int port = 20000;
     string sendmessage = null;
     string recievemessage = null;
     while (true)
     {
         TcpClient tcp = new TcpClient(server, port);
         NetworkStream netstream = tcp.GetStream();
         StreamReader sr = new StreamReader(netstream);
         StreamWriter sw = new StreamWriter(netstream);

         sendmessage = Console.ReadLine();
         sw.WriteLine(sendmessage);
         sw.Flush();
         Console.WriteLine("\nMessage Sent : " + sendmessage);
         recievemessage = sr.ReadLine();
         Console.WriteLine("\nMessage Recieve : " + recievemessage);
         netstream.Close();
         tcp.Close();
     }

In Internet usage, I have this error:
No connection could be made because the target machine actively refused it.
I googled and understood that this happens when Server is not listening on this port but my Server was running.
Any idea? Thanks

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Anthony Mushrow15-Oct-08 13:22

Anthony Mushrow

15-Oct-08 13:22

You may have problems connecting to your server machine through a router (from outside of your LAN) unless you have port forwarding setup. So, try setting up port forwarding to forward all requestes made on port 20000 to your server machine.

My current favourite word is: Nipple!

-SK Genius

Game Programming articles start -here[^]-

Pedram Behroozi15-Oct-08 17:50

15-Oct-08 17:50

Thank for reply,
I think line "TcpListener listener = new TcpListener(IPAddress.Any, 20000);" accepts all clients connected to port 20000, am I right? Or maybe I couldn't understand you! Thanks again.

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Anthony Mushrow16-Oct-08 2:43

Anthony Mushrow

16-Oct-08 2:43

Yeah, but if your server is behind a router, then the router will receive the request and have no idea what to do with it after that. So you use port forwarding, that way the router knows where to send the requests to

My current favourite word is: Nipple!

-SK Genius

Game Programming articles start -here[^]-

Mark Salsbery15-Oct-08 13:33

15-Oct-08 13:33

... or a firewall maybe.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Pedram Behroozi15-Oct-08 17:45

15-Oct-08 17:45

Thank for your reply,
I checked firewall settings, my Server is Unblocked.
Does the IP of a machine in a LAN different from its IP in internet? I think, because we can set LAN IP but Internet IP should be unique, right? If so, how can I get my machine's Internet IP?

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Mark Salsbery15-Oct-08 20:04

15-Oct-08 20:04

Pedram Behroozi wrote:
Does the IP of a machine in a LAN different from its IP in internet?

Often it is, yes.

See SK Genius' reply...

If you're behind a router or some other gateway, your WAN IP address
may be different than the address(es) of your server machine's network adapter(s).
In that case, you'll need to configure port forwarding so connection requests
to the global address (on your selected listening port) get forwarded to your
server's local address.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Pedram Behroozi15-Oct-08 23:43

15-Oct-08 23:43

Thank you very much, SK Genius and Mark Salsbery.
I understood that my PC can't be a Server cause my Server IP is not Dedicate, it's Share, so that IP or the IP I gave from http://www.whatismyip.com/[^] can't be recognized by Clients and I have Error.
Thanks you again.

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Mark Salsbery16-Oct-08 4:56

16-Oct-08 4:56

Pedram Behroozi wrote:
my PC can't be a Server

Are you sure?

You should be able to configure the network to allow this.

I run several servers from this very machine, accessible from the internet,
and this machine's address is very different from the public address.

It's an IT issue. If you're at a company, maybe there's an IT person who
can set it up for you.

If it's your own network, study the documentation for your router/gateway -
look for "port forwarding".

If there's absolutely no way to configure access to your server from outside your LAN,
well, then I guess your PC can't be a server Smile | :)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Pedram Behroozi16-Oct-08 9:14

16-Oct-08 9:14

WOW, THAT'S WORK!!!!!!
jasd gskdf as fdau dlasdfsfdjh gkdfjhg@!!!!!
THANK YOU VERY VERY VERY (to infinity and beyond) MUCH!!! Rose | [Rose]

That's work, I AM HAPPPPIEST MAN IN THE WHOLE WORLD!!!!
I wish I could rate you 100000000000000000000000!

I just search for "Port forwarding" and amazingly I found http://portforward.com/[^] which guided me through Port Forwarding configuration of my Linksys router.
AND THAT'S WORK!!!

How can I thank you? Typing capital letters? Poke tongue | ;-P

Actually I can't.
BEST REGARDS Rose | [Rose]

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Mark Salsbery16-Oct-08 9:20