I'm developing an ASP.net web application.
My default page is a simple login screen.
I am using Visual Studio to develop the application.
It will run using Visual Studio and when the data is entered to the text boxes and the button is clicked, it sends the request to my own server running Windows Server 2012 with SQL Server 2014 installed.
I will also mention that the ASP application is being created as a secondary application for an Android application. The Android application is using the same database over Internet connection so I know that the server and SQL server both can accept read and write calls.
I have tested the ASP application using WebClient calls to php files which connect to the database (this works on Android) and also OracleClient and SQLClient calls all of which work from Visual Studio on my workstation to the server machine. These all work fine to send and receive data from the database.
The problem is once I deploy the application to my hosting site the calls no longer seem to work. The default login page opens but after attempting to login I receive errors as follows:
Exception Details: System.ComponentModel.Win32Exception: No connection could be made because the target machine actively refused it
[Win32Exception (0x80004005): No connection could be made because the target machine actively refused it]
[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.
Can anyone help me with this?
It sounds like your database is accepting connections from some clients, but not your hosting server. I would try testing a SQL connection straight from the hosting Server and see if a test connection can be successful. If you can get that to work it should work from the web server.
This article Quick ways to test OLE DB Connection String on creating a empty TestConnection.udl file will be helpful. It is easier to try different connection string settings through the Data Link Properties UI. When you save the file, you can see the connection string if you open it in a text editor (assuming it is successful).
If it's not a problem with he connection string, check that you do not have a firewall blocking connections between the Windows 2012 and SQL servers. It could be the widows firewall on either machine, or another firewall at the network level.
Related
When I access the website from the same machine IIS is running on I am able to connect to the database, but not if I try to access it remotely. The only way I've managed to get it to connect is when I specify Physical Path Credentials:
click to open image
This doesn't work for me because, I am using the username as a search criteria when querying the database and this way I always get the same username (the one I specified in the physical path credentials).
I am confused because, when accessing the website locally and remotely I use the same credentials and I get different results.
This is the exception that is thrown when trying to access the site remotely:
ByNadexLoginSystem.Exception: System.Exception:
'SelectDataObject()' failed --->
System.Data.SqlClient.SqlException: A network-related or
instance-specific error occurred while establishing a connection to
SQL Server. The server was not found or was not accessible. Verify
that the instance name is correct and that SQL Server is configured to
allow remote connections. (provider: Named Pipes Provider, error: 40 -
Could not open a connection to SQL Server) --->
System.ComponentModel.Win32Exception: Access is denied --- End of
inner exception stack trace
I have tried adding folder permissions as pointed out here:
ASP.NET Application page not working on clients computers with no success whatsoever.
The SQL server is configured to allow remote connections.
I am sure it is a permissions problem I just can't find where. Any ideas?
I found the solution to my problem, I want to give credit to Sean Lange. Thanks to his question it gave me a line of investigation to follow. While going through msdns documentation here https://msdn.microsoft.com/en-us/library/bsz5788z.aspx I found this:
If SQL Server is on a different computer than the Web server, the
Windows identity must be able to flow across the network to the remote
instance of SQL Server. (Windows networks that have been configured
appropriately with Kerberos authentication are able to do this.)
However, depending on the settings in the identity configuration
element, the Windows identity established on the operating system
thread for ASP.NET applications may not be able to flow properly to
the remote SQL Server.
In IIS, only Basic Authentication logs users on with a security token
that flows across the network to a remote SQL server. By default,
other IIS security modes used in conjunction with the identity
configuration element settings will not result in a token that can
authenticate to a remote SQL Server.
Enabling Impersonation and Basic Authentication ( disabled Windows Authentication ) solved it!
Tech used:
Visual Studio 2015
ASP.NET 5 MVC 6 RC1
Identity via EF 7
I've successfully made a connection to a remote MSSQL server using the Server Explorer UI within VS2015. When I say "remote", I mean not on the same machine as my dev machine, but a machine that is local to the network.
Here is the connection string, which is the same in the Server Explorer (works) and the appsettings.json (doesn't work):
"Data Source=DBSERVER\INSTANCE1;Initial Catalog=MyDb;User ID=ASPNET-Db-User;Password=thepassword"
I'm using SQL Authentication in both cases.
When I copy the connection string from the server explorer and plug it into appsettings.json and try to connect to the db in order to create an Identity user account via the "register account" view, I get a connection error:
SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)"
It seems that, clearly, the SQL instance is reachable, but somehow ASP.NET isn't able to connect to it.
Any idea how I might trouble shoot this?
I tried the same code in MVC5 and everything works as expected. I believe this to be a MVC 6 error and have opened a bug report at
https://github.com/dotnet/corefx/issues/4586
After chatting with the folks building MVC 6, it turns out that the CoreCLR does not support named pipes. Using a fully qualified address and an explicit port sorts the problem.
I developed an ASP.NET web application and it worked fine locally with IIS express.
I created deployment package and installed the application on my Windows 2012 server.
When developing the application, I was using an mdf file with localdb v11.0. On the server, however, I wanted to use sqlserver express. I changed the connection string to
Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\nameoffile.mdf;Integrated Security=True;Connect Timeout=30
After making this change I was able to connect to the application from another host on the network. Viewing data and using filters/search (built into stored procedures) works fine.
The error occurs when I try to insert new records or delete records. The message is:
Server Error in '/Nameofapplication' Application.
A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: SQL
Network Interfaces, error: 50 - Local Database Runtime error occurred.
Cannot create an automatic instance. See the Windows Application event
log for error details. )
I've turned off the firewall, allowed remote connections, started sql server browser and agent and various other solutions that I've found from googling without any luck.
Any ideas about how to solve this issue?
I am trying to connect an ASP.NET 2.0 application hosted on a client machine to an SQL server 2000 instance which is installed on a domain controller running windows server 2003 (I appreciate this is not best practise, but it is something I cannot change). I am using SQL server authentication, not Windows authentication.
During debugging, the following error is displayed at the point the 'connection' is attempted within the web application (not on running any object within Sql Server):
"An error has occurred while establishing a connection to the server. When 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. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"
I have done some research, and have checked a variety of things:
1) I am certain the conection string is correct - in fact I built a little Windows app that uses the same connection information and connection succeeds...
2) This is limited to the web application - a windows application running on the remote client machine connects just fine using the same connection string (see 1).
3) The firewall settings on both computers do not prevent the connection (see 1).
4) I can ping the windows 2003 server (see 1)
5) The SQL Server credentials definitely have the rights to the objects needed
6) If I (temporarily) put the web application on the windows server 2003 and run it, it loads and runs fine (using a browser on a separate machine, or on the client machine I am trying to connect) - suggesting this is only an issue with a remote connection, and confirming the connectivity between the machines again, and also confirming the necessary security right of the SQL Server user.
7) I can start query analyser on the client machine and using the same SQL server credentials, can run the same queries on the target database just fine.
Stumped. Please help!
You need to go into the SQL Server Configuration Manager and make sure the Named Pipes option is turned on. It is not turned on by default when you install SQL Server.
Because of the research I did in the original question covering the ability of a windows app to connect but not the ASP.NET app to connect from the same machine, and the confirmation the web app was working on the server itself, I was convinced SQL server was set up correctly, that connectivity and firewalls were not a problem - it must have been a difference in the security credentials of the windows app versus the web app.
The windows app runs in the security credentials of the logged on windows user and authenticates using that, whereas the webapp runs in a restricted account and does not pass these credentials over when connecting to SQL server by default. I simply added to web.config, which impersonates the user account within which the web app runs, and it all worked!
Problem solved.
I can neither login from my application nor connect using the wizard to my Membership Provider on my local machine. My other DBs can connect from my application just fine. My connection string is correct, it has not been changed (I was able to login using membership previously, this is a new issue).
I created a new App to see if it could be the config, threw a login on it and registered and ran into the same issue.
This is the error message I am getting: "A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) "
Though my other DB can connect I still checked:
TCP/IP enabled
Multiple connections enabled
Firewall down
Correct instance of sql server being referred to in Machine config.
Also, my network service account has rights to the DB, but should there be an ASPNET user?
I can't think of a single thing I have changed to this machine since this was working previously.
Thank you.
EDIT DETAILS: There are no aliases, yet, but if my other connections are working that shouldn't be the issue. I understand these things can be wonky though, so that's something I'm going to try now. Thanks. I will also try and take a look at what's going on while trying to connect. Best way: event logs?
I am using Windows Auth, I'm connecting locally, using Windows 7 and SQL Server 2008 along with VS 2008. I can connect with Management Studio and query the DB, yes. NetworkService account has rights to the DB.
Check the Server name in the connection-string if the Sql-Server is in the same machine with the web application use "."(dot) without quotes instead of the computer-name in your connection string.
Have you tried sniffing it to see if there's anything you can see on the wire when the connection attempt is made?
Are there any aliases around the server/DB name? Have you tried creating one and connecting to it?
Are the other instances you can connect to on the same machine? Same SQL Server instance?
If you use impersonation, does the problem go away?
It sounds like you can connect to one database, but not the one you need. Is that correct?
The ASPNET user is a Windows XP thing. You should generally use NETWORK SERVICE for server-based deployments.
So, you can connect from Management Studio, but not from IIS? What identity are you using for the IIS AppPool?
Can you connect if you use Cassini (the web server that comes with Visual Studio)? That should pass through your user ID.