C# httplistener error if remote ip

Question

I created a httplistener and it works only with localhost as a prefix. It show an error if I change it to a remote server ip.

Here's the code:

 HttpListener listener = new HttpListener();
        listener.Prefixes.Add("http://*:8080/");  // I need localhost replaced with remote ip
        listener.Start();
        while (true)
        {
            // Wait for a client request:
            HttpListenerContext context = listener.GetContext();

            // Respond to the request:
            string msg = "You asked for: " + context.Request.RawUrl;
            context.Response.ContentLength64 = Encoding.UTF8.GetByteCount(msg);
            context.Response.StatusCode = (int)HttpStatusCode.OK;

            using (Stream s = context.Response.OutputStream)
            using (StreamWriter writer = new StreamWriter(s))
                writer.Write(msg);
        }
        listener.Stop();

THis is the web client:

   using (WebClient wc = new WebClient())        // Make a client request.
                    wc.DownloadString
                      ("http://"my public ip"(on  my router):8080/lg.txt"); //port forwarding is set
                MessageBox.Show("received");

It works only if I change "my public ip" to my local ip Any ideas?

Answer 1

Is your Windows Firewall on? Try disabling it and see if that helps. You may need to actually disable the Windows Firewall service (in your local services list).

Answer 2

Firstly, check the firewall. Perhaps more likely, though, is http.sys, which is used by HttpListener - you must make the prefix available to the account via "netsh". You can check this by running as an elevated admin account briefly - If it works it is probably a http.sys permissions issue.