MSSQL Linked server login timeout

Question

I have SQL running on several servers and I want to create DB links between the main server "A" and several other "child" servers (each one with their own SQL instance).

I've successfully created a DB link with all of these "child" servers but 1 (Lets call it server "B"). When I try to register a DB link to "B" server using the SSMS GUI I get back below error:

Named Pipes Provider: Could not open a connection to SQL Server [53] OLE DB provider "SQLNCLI11" for linked server "B" returned message "Login timeout expired". OLE DB provider "SQLNCLI11" for linked server "B" returned message "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.".

However, I can open a connection with the SSMS on the "A" server to the "B" server using the exact same credentials and IP, even run queries without any issues.

All of the server have the same DB layout, same VLAN.

Things I've tried:

• Disabled the firewall on the "B" server.
• Use the sa account.
• Created a different login with db_owner authority.

But still I get that error message.

Any ideas on why a "direct connection" from the "A" server SSMS works without any issues, but setting up a new Linked Server with the same IP and credentials have a Login timeout expired timeout?

Answer 1

After checking every single aspect of it, I finally found the issue: For some reason our network guy set up a level 3 firewall rule in a Meraki filter for this specific IP causing only "1 way" communication between "A" and "B" servers. Im guessing "direct connection" via SSMS only uses 1 way communication and a Linked Server has a "2 way communication" (?), anyways, once that rule was removed the Linked Server registration worked without any issue.