I have a problem,I run application C# and I get a 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)
???
what?
thanks
The error message pretty much says it all: make sure the instance name is correct (if your SQL server is using instances) and make sure your server is configured to allow remote connections.
How to configure SQL Server to allow remote connections
How to connect to a server instance
Tip for troubleshooting your connection string:
Create a file named "testconnect.udl".
Double click the newly created file.
On the "Data Link Properties" dialog Switch to first tab "Provider".
From the list of providers select "SQL Native Client".
Click "Next>>".
Complete the following information according to your desired connection:
Data Source // your server name
User Name + Password; check "Allow saving passwords"
Initial catalog // your database name
Click "Test connection".
If the connection succeeds save the database link, clicking "OK".
Open the testconnect.udl file with a text editor of your choice and compare the information with your application connection string.
Check the protocols that are enabled for your server.
Run the Configuration Manager; you may need to enable TCP/IP.
Related
I have inherited another SQL database (Version 15.0.4083.2) and have noted some problems with the SQL Agent. Specifically the Agent is not logging any jobs (as I just discovered trying to check logs to debug an issue). I am seeing the following errors in the agent logs:
[298] SQLServer Error: 53, Named Pipes Provider: Could not open a connection to SQL Server [53]. [SQLSTATE 08001]
[165] ODBC Error: 0, Login timeout expired [SQLSTATE HYT00]
[298] SQLServer Error: 53, A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. [SQLSTATE 08001]
[382] Logon to server 'NotMyClient' failed (ConnLogJobHistory)
(Server name substituted)
This is saying to me that the agent is trying to attach to an incorrect servername/instance. I have then checked the agent properties, i.e. right click on agent, and under Connection it also lists 'NotMyClient'
However when I click on View connection properties the correct IP and computer name.
I have looked at several options for correcting this, but the majoity of answers seem to basically consist of wiping the database, not an option in this case. Also seen a suggestion that the instance name is incorrect, but can see no way of changing the instance name on the server agent.
Any suggestions are greatly appreciated.
i'm a new to stackoverflow but maybe i may also ask a question. I also hope i can help others to find solutions regarding their issues.
So, here we go. I moved a database from an old SQL server to a new one. While trying to configure the application to use the new location of that database shows up an error message like this:
Cannot connect to \MSSQLSERVER.
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: 25 - Connection string is not valid) (Microsoft SQL Server, Error: 87)
The parameter is incorrect
So i started an analysis to solve this issue. And i checked those things:
DNS resolution -> check
ping to the new SQL Server -> check
Firewall disabled -> check
Remote connections on SQL Server enabled -> check
Still receiving this error message. I configured the SSMS on the application server and ran that as SQL server service user without any success.
SQL Server browser is running
TCP/IP is enabled using the default port 1433
I am not sure regarding the SQL server instance name. IMHO it is shown in the service name and the default instance name is MSSQLSERVER. The error message mentions that the connection string is not valid.
So, at this point i don't have any further ideas.
Greetings,
Chris
[EDIT] I don't use any specific connection string because i connect using SSMS.
enter image description here
[EDIT2]
I was able to connect locally using the hostname (not localhost).
All tests below do not use an instance name
Test Result
-----------------------------------------------------
Locally, hostname, AD Auth Success
Remote, hostname, AD Auth The target principal name is incorrect. Cannot generate SSPI context
Remote, FQDN, SQL Auth Connection string is not valid
Step 1: Login Authentication Windows or SQL Server
Check your login Authentication whether its Windows or SQL Server.
Step 2: Use (.) (dot) instead of complete server name
If you are using local MS sql database then you can use (.) (dot) instead of complete server name.
Step 3: Enter Correct Host Name
Enter your correct host name: (hostname\SQLEXPRESS) my_hostname\SQLEXPRESS (in case of SQL Server Express) or (my_hostname\mssqlserver).
Step 4: Try localhost slash () then host name
You can also try localhost slash () then host name, here is sample as (localhost\SQLEXPRESS) or (localhost\mssqlserver).
After setup I can't open my SQL Server Management Studio:
TITLE: Connect to Server
Cannot connect to 0.
ADDITIONAL INFORMATION:
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) (Microsoft SQL Server, Error: 53)
The network path was not found
In my case what it worked for me was the Hosts file in the folder C:\Windows\System32\drivers\etc
I was trying to connect into a SQL server with a name that has an entry in the HOSTS file; however, the IP in the HOSTS file was unreachable - Nonexisting -
First, I connected using my SQL client using the IP address and it was no problem.
Next, I delete the entry for the SQL server name in the HOST file in the folder C:\Windows\System32\drivers\etc, saved it and again tried to connect into that SQL server using the name that I just deleted from the host file and it went thru without issues.
I hope it helps someone along the way
It happened for me, but it is nor serious problem. If database is in your local, may be u must boot IIS or SQLEXPRESS manually in Services of Windows.
And may be, you are writing incorrect name.
You can try the following:
In Windows, go to Services >> SQL Server related to your instance >> Right Click >> Start
Again in Services >> SQL Server AGENT related to your instance >> Right Click >> Start
Try connecting the instance again using SSMS.
Regards,
Pratik
The error message is saying Cannot connect to 0. That 0 is where it would normally give the name of the instance it was trying to connect to. Which implies that you gave it 0 as the name of the SQL instance to connect to, which is never going to work.
You need to give it the name of the machine where the SQL server service has been installed (or use shortcuts like . or localhost to represent the current machine) and if the instance name was not the default instance name, you need to follow the machine name with backslash and the instance name.
If you want to connect to the local instance via SQL Server Management. You can expand the server name box and click the . Then you can browse the local servers via expand the "Database Engine". Please click the instance name which you want to connect so that you can avoid fat figures.
Browse for Servers
Besides, if you want to connect to the default instance on the local computer, please specify the server name as "localhost" or " . ". For detailed information, please refer to the document.
https://learn.microsoft.com/en-us/sql/database-engine/configure-windows/logging-in-to-sql-server?view=sql-server-2017
I am trying to set up a linked server and running into an issue.
On the target server I have configured a user, let's say Q. I have set the source server to connect with Q's login credentials no matter what user is logged in at Source Server.
However when I try to connect, I get the error
"Named pipes provider : could not open a connection to SQL Server
[1231]."
I have tried enabling and disabling named pipes in the server configuration manager, to no avail.
Also I have seen some things saying it is a security problem. The thing is, I am able to connect from Target to Source using Q's credentials in SQL management studio just fine.
Is there something stupid I'm missing here?
is the firewall at the linked server on?
check if the firewall is blocking the named pipes port, which usually is 445
try telnet to the linked server via port 445
Open Server Objects\Linked Servers, then Properties on your linked server. What did you enter here - maybe you are mapping some existing credentials to target credentials?
You should only check the option "Be made using this security context" and then enter Q and it's login. Also, check the "Server Type" to match the destination (Sql server)
On a side note, if the error were due to not supporting of named pipes, I thing you would get a different error, like "error 28 Server doesn't support requested protocol"..
I tried to login to a remote server and I saw the error given at the link -
http://www.microsoft.com/products/ee/transform.aspx?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=2
Message says -
Message: An error has occurred while establishing a connection to the server. When connecting to SQL Server, 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) (.Net SqlClient Data Provider)
Which is followed by -
Explanation
SQL Server did not respond to the client request because the server is probably not started.
Arent the message and explanation contradicting each other ? Which one is the correct reason for the problem ? How do i find out the REAL source of the problem ?
They don't contradict each other. They just give different possible reasons:
SQL Server doesn't allow remote connections
SQL Server is not started
To fix it, make sure that SQL Server allows remote connections and is started.
Allowing remote connections can be done in the "SQL Server Configuration Manager":
Start that program on the server on which SQL server is installed.
Navigate to "SQL Server Network Configuration" -> "Protocols for "
Double click on the connection type - e.g. Named Pipes - and set "Enabled" to "Yes".
If you are enabling TCP/IP, make sure to also enable each individual IP address on the second tab.
See this blog post for more info.
Thee program you are using is unable to find SQL server on the port/address it expects to.
This is likely either because it is misconfigured, or because SQL server is stopped.
I suggest you open a desktop login to the machine in question, and see if SQL server is running.
There are other potential causes for this problem, as well: network problems, for example.