I'm having trouble connecting with my .NET 5 web app to an Azure SQL DB.
The weird thing is that I can connect to the DB using Azure Data Studio.
I've configured the Azure SQL Server firewall to accept connections from my IP address, and all of the Inbound/Outbound IP addresses of my Azure App Service.
Before adding my local IP address to the firewall, I could not connect with Azure Data Studio, so that works as intended, but then I use the connection string provided by Azure itself (in ADO.NET format, since I'm using Entity Framework) inside my web app, and the app can't connect to the DB (it times out with 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: TCP Provider, error: 40 - Could not open a connection to SQL Server)).
I can't really understand why my localhost instance can't connect, as the IP address trying to connect to the db is the same as when I use Azure Data Studio!
And also the App Service instance in Azure can't connect either (in the SQL Server's firewall I've also enabled connectivity from Azure App Services!!).
The connection string is of the form
Server=tcp:[my server].database.windows.net;Initial Catalog=[my db];Persist Security Info=False;User ID=[my username];Password=[my password];MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;
Any hints?
EDIT:
to recap as requested,
dotnet run locally doesn't connect
containerized app service doesn't connect
Azure Data Studio locally does connect
I've found out the issue in the meantime, but I don't understand the cause:
dotnet run from WSL doesn't work; if I run the app from Windows it does work!!
I've therefore changed the App Service to build from source instead of running a containerized image, and it also does work.
Why would running the app locally from WSL instead of Windows result in the Azure SQL Server's firewall blocking me?! Is WSL exposed to the internet with a different IP address?
And why does the same happen to an Azure App Service that runs the containerized version of my app?
Since you can access the server from the same machine, it is not a firewall issue.
There are two possibilities you could check:
The connection string that your program is using is not what you expect. Try logging the connection string.
The server is configured to use named pipes and not tcp. Azure Data Studio is configured to use named pipes and therefore works. Try checking the server configuration.
My WPF application cannot connect to an external SQL Server. The host machine has port 1433 open, has a static IP address, and port forwarding from the IP address to host server has been enabled.
Most puzzling, I am able to connect from SQL Server Management Studio on the client machine using the same connection name, and same server authentication details, but I cannot connect with my .NET application. I am using Entity Framework, which is working until the app is built and queries the server.
Therefore, I have ruled out server hosting issues, and connection string issues, as I'm able to connect while working on Visual Studio, but cannot connect while app is running.
The error (inner exception) is
TCP provider, error 0 - Access is Denied
if you are able to connect through SSMS remotely to sql server there should not be problem for connecting through application using ado.net, you need to recheck your ef configuration and connection string
I assume you are using entity framework 6.
Based on the approach like code first based or designer model based you need to validate your configuration
Please refer to below link
https://learn.microsoft.com/en-us/ef/ef6/fundamentals/configuring/connection-strings
If you are using ef core refer to below link and validate your configuration for connection string
https://learn.microsoft.com/en-us/ef/core/miscellaneous/connection-strings
I'm very frustrated. I have a website running on Visual Web Developer 2008 Express with my local database, everything works great. I also have the same web site running on a production server. Everything was working great but tonight I did a "reset" on production.
I deleted a couple of table, re-created them and inserted data. Everything was ok at this time.
I deleted ALL the files via the FTP.
I used the module called "Copy website" in visual studio and copy the site to the website via FTP.
When I log on my website, here is the error I got:
Server Error in '/' 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: 26 - Error Locating Server/Instance Specified)
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: 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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
Nothing has changed related to SQL connection, this is OLD code that I always used.
My website is completely paralysed because of this and I feel sick inside because I feel there is nothing I can do.
Can anyone help me please?
Your connection string was probably overriden when you copied your new website version on the server. Please check the connection string in web.config and see if it is valid.
If you are connecting from Windows Machine A to Windows Machine B (server with SQL Server installed) and are getting this error, you need to do the following:
On Machine B:
Turn on the Windows service called "SQL Server Browser" and start the service
In Windows Firewall:
enable incoming port UDP 1434 (in case SQL Server Management Studio on machine A is connecting or a program on machine A is connecting)
enable incoming port TCP 1433 (in case there is a telnet connection)
In SQL Server Configuration Manager:
enable TCP/IP protocol for port 1433
I've resolved the issue. It was due to the SQL browser service.
Solution to such problem is one among below -
Check the spelling of the SQL Server instance name that is specified in the connection string.
Use the SQL Server Surface Area Configuration tool to enable SQL Server to accept remote connections over the TCP or named pipes protocols. For more information about the SQL Server Surface Area Configuration Tool, see Surface Area Configuration for Services and Connections.
Make sure that you have configured the firewall on the server instance of SQL Server to open ports for SQL Server and the SQL Server Browser port (UDP 1434).
Make sure that the SQL Server Browser service is started on the server.
link - http://www.microsoft.com/products/ee/transform.aspx?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=-1
check forthe followings :
Make sure your database engine is configured to accept remote connections
• Start > All Programs > SQL Server 2005 > Configuration Tools > SQL Server Surface Area Configuration
• Click on Surface Area Configuration for Services and Connections
• Select the instance that is having a problem > Database Engine > Remote Connections
• Enable local and remote connections
• Restart instance
Check the SQL Server service account
• If you are not using a domain account as a service account (for example if you are using NETWORK SERVICE), you may want to switch this first before proceeding
If you are using a named SQL Server instance, make sure you are using that instance name in your connection strings in your ASweb P.NET application
• Usually the format needed to specify the database server is machinename\instancename
• Check your connection string as well
the cause is that SQL SERVER is stopped from services.msc
a solution for this problem could be starting SQL SERVER from services.msc
I recently had this problem and it ended up being a port issue. My production SQL Server was set up at to be port 1427 instead 1433.
Just change the connection string to be
...data source=MySQLServerName,1427;initial catalog=MyDBName...
Hope this helps anyone who might be seeing this same issue.
I had the same problem with SQL Server 2008 R2 and when I checked "SQL Server Configuration Manager" My SQL Server instance had Stopped. Right Clicking and Starting the Instance solved the issue.
we have to enable TCP/IP property in sql server configuration manager
If your server was working and suddenly started erroring out, your server/instance stopped and connection settings were changed somehow.
For SQL Server 2008 here is how you can fit this:
Goto Start > All Programs > SQL Server 2008 > Configuration Tools > SQL Server Configuration Manager > SQL Server Services.
And here you'll see all the instances and their state.
The state of the instance you were trying to connect can be stopped here.
Double click on the instance and then click on connect.
It will connect and now go back and run your application, you will be able to connect with no error.
This solution assumes the error is not being caused by something wrong in your connection string.
In my case it was a very silly error. I was using a library to read the connection string out of a config file, and I forgot to double back slash.
For example I had:
localhost\sqlexpress which was read as localhostsqlexpress
when I should rather have had
localhost\\sqlexpress note the \
I had same problem regarding that i.e A network-related or instance-specific error occurred while establishing a connection to SQL Server.
I was using SQL Server 2005 (.\sqlexpress)` and worked fine but suddenly services stopped and gave me error.
I solved it like this,
Start -> Search Box - > Sql Configuration Manager -> SQL Server 2005 Services >and just Change Your SQL Server (SQLEXPRESS) State to Running by right clicking that service Sate.
I solved this issue by running the following command in an elevated command prompt as specified in this post.
net start mssqlserver
I had the same problem but found that it was because the password for my Service Account for the Database Engine had expired. The solution was to login to that account, fix this, then set the account so password never expires.
My remote sql server was expecting connection at a different port and not on the default 1443.
The solution was to add a "," after your sql server IP and then add your port like so 129.0.0.1,2995 (Check the " , " after server IP)
Please find the image for reference below.
I had the same error, and it turned out .NET created a database on localhost which I wasn't aware of. When I tried to get the site live it didn't create the database, so the code was pointing to a database that was non existent.
Hopefully this might help some other people out trying to troubleshoot.
I was using Microsoft SQL with asp.net MVC , it was working fine but today morning it gave me error :
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) (.Net SqlClient Data Provider)
I tried to Enable TCP/IP. I also started SQL in configuration manager but still cannot login to SQL Server 2014 using cloud server. It was working fine. I don't know what has happened to it.
Thanks
There is a really good YouTube vid at the bottom of this web-page so you can rule out a few more things - failing that I would have the server rebooted.
SQL Authority
In MS SQL Server Management Studio, have you checked the Properties of the SQL Server to ensure that Allow remote connections to the server is ticked?
If so then I would have to agree that it an on the Cloud Server rather than an issue with the SQL database.
Are you able to reboot the Cloud Server?
MS SQL Studio 2014 doesn't work very well with SQL 2005 or older if you running an old database version
You may want to ensure that the cloud server is allowing connections from your remote IP. It could be that your remote IP address has changed and you are no longer allowed access.
How to open the SQL database firewall for Microsoft Azure:
https://azure.microsoft.com/en-us/documentation/articles/sql-database-configure-firewall-settings/
I'm working on an application using ASP.NET MVC5 and connecting to my SQL Server database with SqlClient (Dapper.NET)
I've been using Local IIS without a problem on http://localhost:port/ but now I have switched over to HTTPS (self-signed key), with a binding of https://www.mysite.com and the hosts file is redirecting that URL to 127.0.0.1
The problem that I am having is the following:
A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error: 0 - The specified data could not be decrypted.\r\n)
This is happening when I am attempting to connect to my SQL Server database with the standard connection.Open() call.
I've read around about people suggesting to restart the IIS server, or to reconfigure the SQL Server database to have encryption forced off. I've checked both of these, but that doesn't resolve the problem.
Can anyone shed some light on what might be going wrong here?
I know why this is...
It's a component available via NuGet called NCrypt which I've just spent 6 hours isolating.
I'm not sure how, but when it's present in my bin folder it interferes somehow with the handshake process between the code and SQL Server.
When it's removed, voila! SQL connects as expected.