Error when connect to remote SQL Server - asp.net

I try to connect to remote SQL Server 2008 Express database from my ASP.NET web application but error throws:
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)
How to resolve that problem. Thanks!

Here's the first thing to check. By default Express only has the shared memory protocol enabled. You'll need to enable TCP/IP protocol for the service (SQLEXPRESS). You do this through the SQL Server Configuration Manager.
Also since Express is a named instance, you'll need to ensure that the SQL Server Browser service is started.
Make sure your connection string is correct. When you are hitting a named instance (SQLEXPRESS in this case) you need to have the data source as yourServer\sqlexpress.
And not to mention, make sure you can ping the box that houses the instance.
Check those things out and let me know if that still doesn't fix it.

i thing your connection string is not correct. Also check a named instance you try to data source as IPaddress\sqlexpress. Like 000.000.000.000\SqlExpress

Related

SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified while connecting via asp.net application

While connecting to SQL Server 2012 Express from Asp.Net application, I get the following exception:
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, I can connect remotely to the SQL Server but once I published the application to the server where the db resides, I got the above exception.
I tried various approaches shared on net but nothing worked for me. Any suggestions?
There should be a problem in your connection string. check the instance name from Sql Server and then paste that instance name in your connection string.
This error is one of the worst, because you normally don't know what exactly the problem is. Here are some possible solutions:
Check that the server name is correct
Check that the instance name is correct
Check that your server is reachable (seems not to be your problem)
Check that the SQL Browser service is running
Check the firewall rules
Sometimes SQL Error 26 just hides another problem with the connection (f.e. SQL Error 0).

SQL Error login with ASP.NET

Hi I am facing a problem with running exercise file of asp.net Quiz engine when try to make login as admin this message show up in the browser
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)
The first place I would look would would be My Computer > Manage and then click on Services. Scroll down to SQL Server, and verify that the service is started (I noticed on my development environments that occasionally my service will not start event though it is set to automatically start. Also, are you running a default or named instance of SQL Server? If your service is started, and you think your connection string is correct, could you include your connection string (obviously omit any username/password credentials) so that I can see what that looks like?

Asp.Net With SQL Server And Asp.net Linq Application

I have an application that uses linq-to-sql with Sql Server Express 2008. When I use the DBML file in a separate DAL project and refer to it to my web project, on execute Sql Server shows this 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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
But when I use the DBML in my web project, debugging is without any problem. But on IIS in Windows 7 64bit i get:
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)
Do these two errors have the same cause? Is the connection string not correct?
I'd suspect that in the first case you have the connection string in the DAL project and not in your web project (where it belongs). Make sure you copy it to the web.config of your web project.
In the second case I think that that the machine hosting IIS tries to connect to the database on your own machine. If so, check the exception: make sure your SQL Express instance is configured to allow remote connections, that the IP protocol is enabled (named pipes if for local traffic), and that your machine is accessible to the IIS machine.
I think, Your connections string is wrong.
dont worry.
check your dbml's designer.cs file. in which you will find '<YourDBMLFile>DataContext()' Constructor.
and Change your Connection string. make sure your connectionstring is correct.

connectionstring in web.config

I have a connection string at web.config. The data source is ".\SQLEXPRESS"
This works fine on local machine, but when I published the website using vs and an error occurred about sql connection.
I think there is some problem with ".". Then I changed it to an IP Address, after that error occurred on both the local and remote machine.
I think the problem lies on the expression of data source. Can anyone help me resolve this?
The error is:
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)
The use of "." is simply a shortcut for "localhost". You must verify that there is a SQLEXPRESS named instance on the machine you are deploying to. If this is not the case, you must specify an appropriate data source. You mentioned using an IP Address which will work, but that will again require an accessible endpoint at that location.
For more help, see the following:
http://www.sqlmusings.com/2009/03/11/resolving-a-network-related-or-instance-specific-error-occurred-while-establishing-a-connection-to-sql-server/

AspNet MVC template issue

I'm having some trouble with the asp.net "register/login system" that comes ready with the AspNet MVC template.
It worked great for me up until recently that I started receiving the following 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: SQL
Network Interfaces, error: 26 - Error Locating Server/Instance
Specified)
I tried running old versions of the code that used to work and they failed as well, I don't know what could have caused it.
Thanks ahead!
Eran
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
Check that you have connectivity to the SQL Server
. Note what you are using to connect: machine name, domain name or IP address? Use this when checking connectivity. For example if you are using myserver
Start > Run > cmd
netstat -ano| findstr 1433
telnet myserver 1433
ping -a myserver
more info at: http://www.sqlmusings.com/2009/03/11/resolving-a-network-related-or-instance-specific-error-occurred-while-establishing-a-connection-to-sql-server/
This problem occur usually when you publish your project. This happens when there is problem in connection string and make sure you SQL server as well as SQL server browser are running.

Resources