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.
Related
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 currently working on an API, to access data from a SQL Server that is hosted locally. My app is being hosted through an Azure web app. I'm also using Entity Framework 6 in my application to access data. Since my data can't be in the cloud, I created an Azure Hybrid connection to create a relay to my SQL Server.
However, I keep running into this error (see below). I don't understand why this happens. I have checked my firewall rules to make sure that connections from Azure are being permitted. I have also verified that my connection string is correct and that I'm using the right port number. I also verified that remote connections are allowed on the SQL Server.
In case anybody is wondering I'm running SQL Server 2012. Does anyone have a fix for this issue? I would really appreciate it.
Thanks in advance.
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.
I have a SQL Server running on Microsoft Azure. I want to connect it to My Project in Visual Studio 2015 Community. I have added my IP address in firewall on server. I have also made my port 1433 open for sql. But when I try to connect to database this error shows up. Error Message in SQL Server
It appears that this is a two step process and you either missed the VM configuration or the Azure configuration. Based on what you said I believe it is the Azure configuration that may have been missed. This blog post appears to highlight the necessary things that need to be done to connect.
https://blogs.msdn.microsoft.com/ggaurav/2014/01/08/connect-to-sql-database-on-azure-iaas-from-ssms/
Below is an excerpt:
The two settings which you have to make sure you are checking are :
Endpoint is configured for the port on which SQL server is listening ( generally 1433) on the VM machine.
Ports are opened on the VM machine. Even though as per the documentation Cloud adaptor takes care of opening the firewall ports,
it doesn’t work for the normal connections which you are trying to
make. Just type in ” wf.msc” and create a rule for both outgoing and
incoming for TCP port 1433.
As soon as you are done with these two, you would be able to connect
to the SQL server on the VM machine.
According to your description, I guess your SQL database is a Azure service, not install SQL on Azure VM.
If I understand it correctly, we should check SQL database firewall settings and confirm the name of your database.
The error code means, this error could occur because either the
firewall on the server has refused the connection or the server is not
configured to accept remote connections.
We can via Azure Portal to check the firewall settings:
Make sure the Allow access to Azure Services is ON,
And make sure your client IP address have added to the Client IP address list.
Also we should confirm the name of your database, make sure we are connect to the right SQL database.
I have also made my port 1433 open for sql. But when I try to connect to database this error shows up.
You also need to enable 1433 port in Network Security Group which related to your VM. Steps below are for your reference.
Find the Network Security Group name which related to your VM in Netowrk interfaces panel.
Open this NSG, click [Add] button in the Inbound security rules panel
Add a rule as following.
After that, we could access the database hosted in VM using following server name format.
Server name format.
[IP address/dns name],1433
For example,
13.81.50.123,1433
My application is throwing error from a client machine of not able to connect to the database. So as a test I use SQL Management Studio 2008 on that same client machine to try and connect to the database and I found out that if I use IP\InstanceName then I can connect but if I use ServerComputerName\InstanceName then I can't connect. I have verified the following:
The server has the same gateway and subnet mask as the client.
I can ping the server using either its IP address or its computer name.
No Firewall on either server or client machine.
Verify Server SQL browser service is running.
Verify Server is set to allow remote connection.
Verify Server TCP/IP is enabled via SQL SErver Configration Manager.
I can connect from a different client machine using ServerComputerName\InstanceName
Both server and client are using static IP setup with no DNS server under IPV4 properties.
Tracert from client to server shows only one hop, that is directly to the server machine IP.
I can remote access the client machine from the server machine or viceversa using host name.
I then go to the server machine and connect using LNKLAB8\Xmark (LNKLAB8 is the host name and Xmark is my instance name) and I connected successfully. However, when I run the command SELECT ##SERVERNAME, the result I got back is LNKLABARIAL8\XMARK
This baffled me, because if I right click on the database properties as per the screenshot below, it shows LNKLAB8/Xmark .. am I going crazy or something weird going on here? after taking at the steps I've taken, do you have any suggestion of how I can get the client machine to connect to the database using the server host name instead of the server IP address?
I've kind of hit the wall on this issue, I'm unsure if I am facing a network related issue or it is a database setting issue.
Edit: When I tried to connect using host name to the server DB I would get the following:
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)
Try add servers IP and Name to c:\WINDOWS\system32\drivers\etc\hosts
1) Make sure you've enabled TCP/IP (Configuration manager), and restarted MSSQL
<= it sounds like you've done this.
2) Make sure you can "ping" by hostname and by IP
<= It sounds like you've done this, too
3) Make sure MSSQL Browser is running
4) If you're using Windows authentication (vs. SQL Mixed), then make sure you can authenticate to the remote server:
net use \\remote-server /user:<name> <password>
5) Failing all else, you might want to consider reinstalling MSSQL-related components on either/both client or server (for example, MDAC)
Links:
http://social.msdn.microsoft.com/Forums/sqlserver/en-US/4d2ce34a-508f-4a1d-8828-8806ccc12f77/sql-server-2005-cant-connect-remotely-using-host-name?forum=sqlsetupandupgrade
http://blogs.msdn.com/b/sql_protocols/archive/2007/05/13/sql-network-interfaces-error-26-error-locating-server-instance-specified.aspx
https://serverfault.com/questions/384700/error-connection-to-sql-server-using-hostname-instance-or-fqdn-instance-ip
'Hope that helps!
I noticed this:
8: Both server and client are using static IP setup with no DNS server under IPV4 properties.
How is name resolution happening, then? WINS? NetBIOS? Sql Server may not like that. Try checking that you have a working DNS server with the appropriate entry for your Sql Server system, and things may work better.
I have done a small C# Win Forms application, that connects to mySQL database using mySQLconnector. This works perfectly ok with my localhost.
String ConnectionString = "server=xx.xxx.xx.xxx;uid=myuserid;pwd=mypassword;database=dbname";
But I do get following error when I try to connect to remote server:
Unable to connect to any of the specified MySQL hosts.
{"No connection could be made because the target machine actively refused it xx.xxx.xx.xxx:3306"}
I have pinged the server from command prompt and I get response.
I also verified mySQL server settings in remote server database (correct name/ip, portno:3306, skip networking:OFF)
The remote server is accessible without any problem from web server that runs php script and uses same settings as the connection sting I listed above.
The mySQL server is hosted on external shared hosting company 123reg.co.uk with me logging to phpmyadmin using same uid/passwd as like in connection string.
I can't understand what is different between webserver accessing OK, but my C# app having trouble with it??
Can any one please help...
Thanks in Advance
Sam
I've had issues with servers setup so they won't accept remote connections. This is for security reasons mainly. Some places will let you enable it in the CP, but if you have direct access to the server, you should be able to follow these steps.
http://www.rackspace.com/knowledge_center/article/mysql-connect-to-your-database-remotely
Your ip address will be different from the web server.
If your ip address is static you can grant access to your ip address within your mysql database ( https://www.google.com.au/search?q=mysql+grant+access+to+user+from+host ).
I'd recommend using the server to access the database and make your c# application talk to your webserver using ajax/json calls ( https://www.google.com.au/search?q=C%23+Win+Forms+ajax+json ) - that way you're not tied to an ip address for access.
Alternatively you can look at setting up ssh tunnels to your webserver if remote shell access is available so you can get the same access as your webserver. ( https://www.google.com.au/search?q=ssh+tunnels+example+mysql That's what I do myself)