Microsoft SQL Server Error:26

Question

what's the problem?

Cannot connect to ------------------------------

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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)

For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver--1-database-engine-error

Answer 1

Verify that the instance name is correct

First step is to do what the error message says.

Answer 2

This is general error which says that you were not able to connect to the SQL Server instance you tried to connect to. Since we don't know you environment or why you think conncetion should succeed, we can't what is wrong.

Common reasons include:

• Fat-fingering server and/or instance name.
• SQL Server is not running.
• Firewalls blocking the way,
• It's a named instance and the Browser is not running or blocked by firewall.

See furhter this troubleshooter.

Answer 3

Hi @Ahsen Tosun

Please provide details about your environment, whether it's SQL on-premise, Azure SQL VM, or Azure SQL Database.

Are you connecting from your local machine and experiencing issues? Have you checked your network configuration.

Was it working before and failing now, or is it a new setup. Is anyone else able to connect?

Here is Microsoft document for reference for such error-  

https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/connect/network-related-or-instance-specific-error-occurred-while-establishing-connection

And the blog (if its SQL on-premise or Azure SQL VM)

https://www.mssqltips.com/sqlservertip/2340/resolving-could-not-open-a-connection-to-sql-server-errors/

Thank you.