Question: How can I hide a SQL Server Instance from clients attempting to make connections? SQL Server Browser allows a client is able to find a SQL Server Instance, but I want to hide the instance from the client.
Answer: It is possible to hide the SQL Server instance using the SQL Server Configuration Server.
Expand SQL Server Network Configuration | right click Protocols for my_instance | Click properties
Use the HideInstance box in the Flags tab. Change it to Yes, and restart the SQL Server Instance
If you attempt to connect , after you have changed the HideInstance box to Yes and restarted the SQL Server Instance, the following message appears on the client
Sqlcmd: Error: Microsoft SQL Server Native Client 11.0 : SQL Server Network Inte rfaces: Error Locating Server/Instance Specified [xFFFFFFFF]. . Sqlcmd: Error: Microsoft SQL Server Native Client 11.0 : Login timeout expired. Sqlcmd: Error: Microsoft SQL Server Native Client 11.0 : A network-related or in stance-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 i f SQL Server is configured to allow remote connections. For more information see SQL Server Books Online..