Connection failed - SQLState ‘08001’ in SQL Server

When creating a connection to SQL Server using an ODBC driver, you might receive this error:

Connection failed: SQLState: '08001'

Here are some common causes and corresponding fixes:

1. SQL Server service is not running on SQL Server.

You can try to start or restart SQL Server services, including SQL Server Database Engine, the SQL Server Agent, or the SQL Server Browser service.

2. SQL Server Browser service is not running on SQL Server.

This might cause the issue sometime so make sure to enable the “SQL Server Browser” Service and set to start Automatically.

3. TCP/IP protocol is not enabled for SQL Server.

Make sure the TCP/IP protocol is enabled by logging in to the SQL server, navigate to the “Sql Server Configuration Manager”, then enable the “TCP/IP” and the “Named Pipes” Protocols.

4. Firewall on SQL Server is blocking TCP port of SQL Server.

Check and reconfig the firewall rules to allow SQL Server access.

5. Firewall on SQL Server is blocking UDP port (1434) of SQL Server browser.

Again, check and reconfig the firewall rules to allow SQL Server access.

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