Check If A Port Is Open Using Sockets?
Feb 16, 2010
I have written some code to check if a port is open. I'm currently trying to work with the system.net.sockets name space.I know that the easy way out would be to use AxWinsock, but I don't think the AxWinSock is very cool, nor do I think it's very professional when trying to make network applications in VB.NET.
I've got this Error message : Socket Exception Was unhandled, No connection could be made because the target machine actively refused it 127.0.0.1:1 IDK, Like I said, I'm new to the System.net.sockets namespace, I'm pretty good with other stuff in VB.NET, but when it comes to the serious stuff like the system.net.sockets namespace, I'm not so great.look at this code and tell me what I am doing wrong, I've manged to get this far, and I don't want to just give up and continue watching my movie.
[Code]....
View 3 Replies
ADVERTISEMENT
Nov 24, 2011
I have an application which need to send data to particular system on specific port. But the application gets hang if the target system port is closed.
I Want to know if a particular Port is open on a specific IP address so that i can continue my next task. PBL (Visual Studio 2010 Ultimate)
View 11 Replies
Jul 13, 2010
I want to check if a specific TCP Port of an IP address is open.
How can I realise that?
View 12 Replies
Jun 29, 2009
I am trying to use the my.computer.network.ping method to check a server's ping. what I realize is that I need to open a socket. I do not know how to do that. I have a textbox with the website url.I have a label that will display ping.
View 2 Replies
Mar 19, 2012
i have a task to create a TCP Server (a program that is listening on its network card interfaces for incoming data stream).I have search on the internet and i found that i can use two methods : Socket or TCPListener class.I have created an example for Socket class, but i wondering how could i test it? I need to check that if another computer in the network send some string data to the listener computer , then this message should be displayed.Here is the example from microsoft that i am using for TCP Server using Socket:
Public Shared Sub Main()
' Data buffer for incoming data.
Dim data = nothingc[code]....
But it does not work because of the PORT setting.If in the TCP Server i have "Dim localEndPoint As New IPEndPoint(ipAddress, 0)" the client crashes, but if i change the port from any (0) to 11000 for example,the client works fine.Do you know why?
Later edit2:Maybe i should have started with this question:Which method is recommended for my scope?asynchronous or synchronous method ?
View 2 Replies
Dec 28, 2010
I'm making a Visual Basic GUI application to display whether a number of my ports are open for people to know whether things like my website and my Minecraft server are open.My problem is I have absolutely no idea how to do this in Visual Basic.Basically, I'm asking for something which sends a signal to an IP with a specific port, if it is open then return true, if it's closed, return false. Similar to: http:[url]....
View 1 Replies
Jan 29, 2011
i am trying to get this code that worked in VB6 just fine to work in VB.net 2008. It doesnt seem to want to connect (but has no error after it goes past the sockMain.Connect().
[code]...
I get the It doesnt seem that the server is running. Please check it and try again. error.
View 3 Replies
Jan 17, 2012
I need to transfer data between several computers in a network using my app. I thought of using TCP ports. how to open and use them? I only want to make a file transfer and chat app that works offline.
View 3 Replies
Sep 18, 2011
I am working in Visual Basic 2010 and need to check if a port is alive on an ip.I am currently using this code
If My.Computer.Network.Ping("85.250.180.71") Then
TextBox2.Text = "Server Online"
Else
TextBox2.Text = "Server Offline"
End If
View 7 Replies
Jun 9, 2011
how to open all serial port in vb.net? i know how to open by getportname..but how to open all??can we do it?
View 2 Replies
Apr 1, 2010
how can i open port 433 in my windows
i don't want any code just i want to open open it
View 2 Replies
May 31, 2010
i want to work with it in vb. 1st i want to check if port is already mapped or not, if not then map it and once done remove the mapping. The one way is using shell and pass command in it, but not sure how to get already map status and also wondering if there is any other method to get it done.n :)
View 1 Replies
Jan 8, 2011
I am very new to this but i have with alote of help maked a program that comunicates with a relay board over rs232.
[code]...
View 2 Replies
Feb 9, 2010
I'd like to check to see if a serial port even exists. I know that if it doesn't, there is an error thrown when you do a port.open So, I would imagine that doing a simple IF port.isopen won't work?I looked at all the methods on the class and don't see anything obvious on how to do it.I just want to see if the hardware exists on the PC and set a boolean variable if it does when the form loads.
View 3 Replies
Sep 1, 2010
Public Class my_class Dim WithEvents COMPort As New System.IO.Ports.SerialPort
Public Sub FindReader()
Dim ports As String() = IO.Ports.SerialPort.GetPortNames()
Dim port As String
For Each port In ports
[Code3]...
When it runs, it shows a single COM port "COM1". I am assured that the device attached to it is a standard 8,n,1 and uses 9,600 baud. The exception is "Acess to the port 'COM1' is denied".
View 1 Replies
Aug 10, 2009
I am trying to open a GPS device on a serial port but no matter what I try I just keep getting an IOException. This is on a pocket PC BTW.
[Code]...
View 2 Replies
Aug 6, 2009
I have this problem says that "the portName cannot be set while the port is open". When this errors occurred, my application on sending sms could not work. Before I edit the application can work but after making some changes and ask help in this forum, the application does not work and gives errors and it says "the portName cannot be set while the port is open".
Imports System.Windows.Forms.Form
Imports System.Text.Encoding
Imports System.Threading
Imports System.IO.Ports
[code]....
View 4 Replies
Feb 13, 2009
How to open/Read/Write in USB Port
View 3 Replies
Feb 25, 2009
I wrote a program that uses the following class from that site: VB.NET Tutorials - Serial Port Communication In VB.Net. The problem is that I cannot open a virtual serial port, and the second is that I want to make the communication asynchronous.
This is the subroutine which reads from the port:
#Region "comPort_DataReceived"
''' <summary>
''' method that will be called when theres data waiting in the buffer
''' </summary>
''' <param name="sender"></param>
[Code] .....
View 10 Replies
Jul 20, 2010
In VB6 I had to always check if the port was open or not. But with VB.NET and the new Serial Port control I don't see any.If SerailPort1.Open then statements. In fact when I tried to use the code I got Expression does not produce a value.So does this mean that we no longer have to check to make sure the port closed?Is there a way to check if the port is open or not?
View 1 Replies
Mar 2, 2010
I have a class that inherits from the TcpListener, this class Shadows the Start method just to call the base Start() and the base BeginAccept Tcp Client(). From time to time the method is called but the port is not opened (netstat does not show the port open).[code]The class that uses the ExtendedTcpListener implements the IDisposable pattern and inside the Dispose the ExtendedTcpListener.Stop is called.The stop text is not present at the logs when the problems happens.
View 4 Replies
Jan 10, 2011
I have a few USB devices that use standard Microsoft Virtual COM Port drivers. More specifically, I believe they use the "Usbser.sys" driver. Whenever I plug my USB devices in, they always shows up in the Device Manager as a COM port, however, sometimes I am unable to open that COM port. This problem occurs on both Windows XP SP3 and windows 7 machines (The only operating systems I have tested this on).
To be a little clearer, I can plug my USB device in, and then successfully open the COM port. I unplug my USB device, then plug it back in, and I am unable to open the COM port. The only solution to this problem is to restart my PC. Is there any solution in VB.net to reset any entrees made to the Windows system when the USB device is plugged in? Has anyone come across this problem and resolved it via a VB.Net solution?
View 10 Replies
Aug 15, 2011
How do i check if specific port is blocked by Windows firewall , both in incoming and outgoing connections.
I've seen code samples such as this one:
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim host As String = "localhost"
Dim port As Integer = 6900
[Code]....
But how can i know if the exception is thrown specifically because of firewall blocking, and not because of other socket errors?
View 1 Replies
Dec 17, 2011
I am in need of a way to check the status of a IP and Port. I've been looking around all day and still haven't found the correct thing.
View 8 Replies
Jul 8, 2008
I have a programme that accepts data from a serial port. If I close the port and then the form no problem. However if I try to close the form with out closing the port it appears to hang. I have tried closing the port in the forms close event but this did not solve the problem.The data recieved event is as below and UseData is the private sub which actually handles the data. Usedata contains the code line Dim InputText As String = SerialPort1.ReadLine
Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Me.Invoke(New myDelegate(AddressOf UseData), New Object() {})
End SubI am aware that this event runs on another thread and I have seen but cannot now find information about closing multiple active threads.or do I have to "uninvoke" the delegate
View 1 Replies
Jan 15, 2010
I tried to make a winsock program.But when i run, i have a SocketException "No connection could be made because the target machine actively refuse it."Any suggestions on what i should do? Im using 17477 port.By the way Im using my own computer to test it. So i have no idea why.How should I open this specific port in my own computer?
Is it possible that I could include it to could into my program so that i don't need to open the ports of each computer? Below is my code.
[Code]...
View 6 Replies
Aug 14, 2009
I'm having this problem with a networked app in vb.net. If the program exits normally the port closes fine, however, if it crashes sometimes it remains open and I am unable to close it. The next time I run the program it is unable to open the port because it is already in use. Here's the exception: 10048: Only one usage of each socket address (protocol/network address/port) is normally permitted on how I can reclaim this port, or how I can close it? I tried using the reuse address socket option
[Code]...
View 7 Replies
Oct 20, 2009
I need to check if port exist in the firewall list I am currently using this piece of code to check if port 80 exist do something if it doesn't then add it. This works fine but I feel It should be cleaner[code]...
View 1 Replies
Dec 20, 2009
What I am doing is creating an app to send and receive CNC programs to machine tools via the RS232 interface. At the moment I am testing the software with 2 laptops linked together through a cable I have made up. which all works. I have added a serial port to my form 1 and using the code below I can send and receive data. However with the send button I can open the comm port send the data and then close the comm port (No Problems there). With the receive button I want to open the comm port receive the data and close the comm port. The problem I have is checking when the app has finished receiving data so I can then close the comm port
Private Sub Btn_Send_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btn_Send.Click
Try
[Code]....
View 2 Replies
Oct 2, 2009
I am trying to write something through serial port to my device. Before that, I added the data received handler to read the data when the device response with some data. The problem now is how can i check the status of the data received event? I need to know when the data received event has started or has ended before I can proceed to do some other task like check if the result is successfully receive.
View 2 Replies
