Can't Seem To Establish A Connection Between My Two P2P Applications Over The Internet
Sep 14, 2010
I just can't seem to establish a connection between my two P2P applications over the internet(LAN works perfectly fine).
I have tried the following.
- Disabling Firewall
- Changing Port
The only way I can establish a connection is if I'm connecting to the same computer using the universal IP or the local. Does anyone have a fix for this? Oh and here is the error that I receive when trying to connect over the internet:
System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 255.255.255.255:8787
at System.Net.Sockets.TcpClient..ctor(String hostname, Int32 port)
at P2P_Client.Form1.Msgtxt_KeyDown(Object sender, KeyEventArgs e) in C:\Users\Administrator\Documents\Visual Studio 2008\VB Projects\P2P-Client\P2P-Client\Form1.vb:line 32
I'm developing a device app in VB.net that will access a SQL Server database. I need to establish a connection when the app is launched, and keep the connection open until the app is closed. I've done the following:In the Master Module:
Public CNN As SqlConnection
In the Main menu form load:
CNN = New SqlConnection(sqlConnString) CNN.Open()
Then when I want to read from the database:
Dim sqlDR As SqlDataReader SQL = "SELECT Name FROM Table"
[code]....
When I run the same code without the global CNN, but rather dim the connection inside the Select function, all works well.
This will happen at random, and I can always just catch the error and re-establish connection to the server, but I am confused as to why. When doing lots of inserting into the sql server, I only establish one connection that is public, instead of many little connections. I had my doubts on a public sql connection, but it's been running great, and I've seen no problems until this morning. Again, this random moment I hit an error that stated, sql connection state is broken. Is it bad practice to just accept this error, and when it happens, re-establish the connection?
I'm using Visual Studio 2005 and SQL Server 2000 for my vb.net desktop application..I'm having a SQL Server exception saying that "connection can't be established to the server.hen connecting to SQL Server 2005 this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. Also showing
i use vb 2008 office 2007 , it's a powerpoint add-in application. I need to use a window form as a bluetooth interface.the working procedure is like that when i click the Enum button, it will help me to search for available bluetooth devices.but now i have an error, it shows "WCL ERROR: Specified transfer is not available"
I have being trying without success to create a program that can establish a SSH connection with [URL] on a changeable post with a set username and password. The program when done will configure IE proxy settings and establish a SSH connection to [URL] to allow the user to browse the internet without restrictions.
I'm designing a web service in ASP.NET and VS2008, and am using typed datasets for retrieving table data. These work well and establish their own connections through their associated TableAdapter objects. Edit: I'm using VB, BTW!I am now attempting to run a custom SQL string using a DataAdapter and a Command object, however I need to reference a Connection object in order for the Command to work. What is the best way to handle this?hould I:a) Create a global connection object using Global.asax, retrieving the connection string from web.config? (I've been trying that one already, with not much success)b) Create a class-level connection object using the InitialiseComponent method, also retrieving the ConnectionString from web.config?c) Retrieve a Connection from one of the TableAdapters that I've already created in my typed DataSets?d) Something else I haven't thought of yet?
I want to start a new project on PC and Mobile Phone. But i'm still have so many question about the communication between PC and Mobile.
My project List: 1) My idea is establish a connection between PC and Mobile through IP address in first, but my question is 'How to do it' ? izit same like PC to PC by using Winsock open a port to access? i'm using VB.Net 2005 for PC and Net60 for mobile.
2)My mobile phone Nokia 6220 Symbian OS is support GPRS/3G. Since the GPRS/3G can connect to the internet, izit means mobile itself have a IP address and service provider in order to surf the web? So, can i connect my mobile phone to PC through this gateway?
I have a project in Visual Studio 2008 and there is a working data connection to a MySQL database. In other words, I can query the db directly from Visual Studio and it will display the results.
I've tried a couple of approaches that I found online for writing a connection string and accessing the db, but no luck yet.
All I'm trying to do is code a button to query the db and then reset the text property of a label/textbox to display the results based upon another label/textbox value.
The pseudo-code I am imagining is something like this:
Private Sub query_submit_button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles query_submit_button.Click result_textbox.Text = SELECT field FROM table WHERE otherfield = key_textbox.Text End Sub
I didn't see any related questions posted on SO - forgive me if I missed one that already exists and this is a dupe.
I am confused; I am using VB2010, IBM.iSeries.DB2 on an as400 V5R4. I am trying to establish an OLEDB connection, and return the values from the selected table to a DataGridView. I had one of the admin's make me file named GARBAGE, in the Rprtaccess catalog. In the past, I have been able to connect via access and an ODBC connection. My project is too big for access, and the SQL middleware we have is clunky and not user friendly. This is a program that will generate the SQL statements, specifically the WHERE: clause and populate the datagrid with the selected criteria. In essence I am making a user friendly striped down program, that has variables that are manipulated by the end user, and the rest, referenced tables and libraries are coded.
Imports System.Data.OleDb Imports System.Exception Public Class Form11
I have a windows application developed in VB.net 2005. The application is installed in several machines.Is there anyway when I do any modifications and publish the code it updates in all the machines.
What is the best practice way of detecting internet connection?
From Windows Vista onwards, a status is set in windows that is displayed in the task bar. However, I cannot call this function/api/whatever, since some of the client pc's are still on xp, and only due for upgrade in 18 months.
so do i use and request something like [url]... to try and see it it works, and on the catch block set the return value to false, or is there another way?
Second part of this question, If no network connection is available, I can use [url]... to dial a connection. Will this use internet explorer's settings, or dial the connection marked as default in DUN?
Public Sub Life(ByVal AnyEvent As Object) Dim myNewLife As New Life Dim Happiness As New Collection Happiness.Add(AnyEvent) myNewLife.Experience(Happiness) End Sub
In MC65, SIM card is already inserted. Any web site can be browsed.
In my application, there is sending email feature using Rebex. Sometimes, it cannot send email. So I tried to browse IE and I'm beware if 3G connection signal appears, sending works properly.
Around connection signal on Screen, there is "H" symbol. What is it?
For my case, it's not good to switch 3G connection by browsing IE. how to handle it.
I'm writing a Silverlight 4 application and would like to check when opening the installed out of browser application, whether there is a valid internet connection (to then download some data from my website). I realise that I could put a try catch around a WebRequest but that seems a bit hacky to me.
EDIT: What I meant by valid internet connection is just connected to the internet
This is the work of one responder for the most part, and is not indicative of the quality of most of the posts.But you can judge that for yourself.
If you are writing a program that is used to monitor the status of your network, then this thread may not be of interest.
If you are an application programmer that uses network resources to accomplish your goal, i.e. you are using SMTP, FTP, HTTP, NNTP, NTP etc., and you think that you need to check for a connection first, then read on.Follow up to this.Before getting all geeky let's take a little detour...
Five days a week I get up, eat breakfast, check my email, forums, etc., take a shower, get dressed, and then drive to school.Many of you probably have a similar routine.What is interesting about that is not what we do, but what we dont do,because of our expectations and experience.Here is what I dont do.
I dont stick my finger in the electrical socket to see if there is electricity for the coffee maker and toaster.I dont fire up the command prompt and ping some host on the internet to see if I have connectivity.I dont check the battery, tires, water level, clutch fluid level, washer fluid level, etc.,before I drive off.
All of that is based on expectation and experience.So why would you write an application that pings the internet before it did something (SMTP, FTP, HTTP, NNTP, NTP etc)???? Is your experience or expectation that the network will be down?To illustrate and hopefully convince you that, like Oblio, it is pointless, create a new form with three buttons. In the following examples I use a WebRequest / WebResponse as my 'Something'.Here is what some think is a good approach, the classic ping-then-do, what I think you shouldn't do.[code]....What is wrong with this code is that all of the network IO is being done without a Try / Catch block.
I've project where i wanna check if user is connected to internet if he isn't then form must close and another form should show up ! Problem i'm getting is i can't use check it constantly, even if i use while loop
keep looping the following code until condition is wrong or until connection is made While IsConnectionAvailable() = False ' code goes here for when connection to hotflask can't be made[code].....
but here form 2 keep showing up and it crashes system, is there any simple way to do it .
i have developed a little application, which send email to me, it works on direct internet / dsl , but when i run my programm on a pc where the internet access has used a proxy server for clients, my application show a error that could not find host, and failed to send email
We want to developed services to sending fax which should check internet connection after every 10 sec and should be work on all windows operating system.
I cannot use any host like[URL]..to check internet connection because it increase network traffic.
is there a way I can proxify my application's connection to the internet??I came accross System.Net.WebProxy. Here is what I have with it so far:
Dim pr As New System.Net.WebProxy(proxy)Can I set the value of proxy to equal something like 127.0.1.2:80 or do I need to split it into the address and port?Also how do I force my application to connect to the internet through that proxy? Because this is ithe part that is really baffeling me.
In a picturebox/image control (WPF) how can I set an image which displays when there isn't an internet connection?
Basically, I have the picturebox image set to an image online (ie www.example.com/example.png). But how can I set an image to display when there is no internet connection?
Using - VB2008 Express, XP Pro, Connecting to SQL 2005 across the internet The walk throughs have several good explanations although I don't see any about connecting over the internet.
I have an app that gets all the network computers on a local network. Is there any way to block the connection of a computer by the IP/host name? I want to manage my wireless connection at home so that no one can steal my signal.I would use this app on the computer connected to the wireless router.Anyhow, is this possible? Isn't it? Many online games ban the players by IP, so I thought it could be done.
