Microsoft SQL Server connectivity issue from computer within network

Question

I'm hosting an SQL server on a pc that runs ubuntu. I can connect using SSMS with a windows laptop through vpn which gives me a local ip like 10.0.8.0.
However a windows pc that is within the same subnet can't connect with the same credentials that i use with my laptop. The error i get is
"Named Pipes Provider, error: 40 - Could not open a connection to SQL Server" I've tried to specify the server instance and different connection methods.
I even tried to set up a second sql server outside my network and connecting with the troubled pc (also through vpn) ... and that somehow works.
So my question is: what is allowing connections with devices that are in the network through vpn and excluding devices that are in the same subnet?
Is my servername flat out wrong?
ive tried: the localip of the server (which works on vpn), the name of the server (which doesnt work anywhere), the localip and a server instance name...

Answer 1

Hi @Stan Matth ,

This is a default SQL server instance or named instance? For SQL server named instance, we can using below connection string on server name box.

Server name\instance name
Ip, port number

> Named Pipes Provider, error: 40 - Could not open a connection to SQL Server

Please follow below steps to troubleshot the issue,

1. Make sure SQL Server Service is running
2. If a named instance, make sure SQL Server browser service is running. Make sure the instance name is spelled correct and there is actually such an instance on your target machine.
3. Make sure SQL Server is configured to allow remote connections
4. Examine the SQL Server error log for messages confirming that SQL is listening on the expected network interfaces and ports
5. Test server connectivity with PING from the client machine
6. Test port connectivity using TELNET to the server and port (from step 4) from the client machine. For example
   TELNET <server-name> 1433
7. Check firewall settings if step 5 or 6 connectivity test fails

If you have some confuse about the steps, please refer to Resolving could not open a connection to SQL Server errors or Troubleshoot connecting to the SQL Server Database Engine to get more information.

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