A network-related or instance-specific error occurred while establishing a connection to SQL Server

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: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server)

This can be due to various reasons ranging from network issues, server settings, incorrect connection strings, or even SQL Server service issues. Here are some common steps to troubleshoot and resolve this issue:

1.Verify SQL Server is Running

Ensure that the SQL Server service is running on the server.

• Open SQL Server Configuration Manager.
• Check the status of the SQL Server service.
• If the service is not running, start it.

2.Check SQL Server Instance Name

Ensure that SQL Server is configured to allow remote connections.

• Open SQL Server Management Studio (SSMS).
• Right-click on the server instance and select Properties.
• Go to the Connections page and ensure that Allow remote connections to this server is checked

3.Verify SQL Server Configuration

Ensure that SQL Server is configured to allow remote connections.

• Open SQL Server Management Studio (SSMS).
• Right-click on the server instance and select Properties.
• Go to the Connections page and ensure that Allow remote connections to this server is checked.

4.Check SQL Server Network Configuration

Ensure that SQL Server is configured with the appropriate network protocols.

• Open SQL Server Configuration Manager.
• Expand SQL Server Network Configuration.
• Click on Protocols for InstanceName.
  • Ensure that TCP/IP is enabled.
  • If TCP/IP is enabled, right-click on it and select Properties. In the IP Addresses tab, ensure that TCP/IP is enabled for all appropriate IP addresses.

5.Verify SQL Server Authentication

Ensure that the SQL Server authentication mode and credentials are correct.

• Open SSMS.
• Right-click on the server instance and select Properties.
• Go to the Security page and ensure that the Server authentication mode is set correctly like SQL Server and Windows Authentication mode.

Summary

To resolve network-related or instance-specific connection errors in SQL Server, follow a systematic troubleshooting approach to verify that the SQL Server service is running, network protocols are enabled, firewall settings are correct, authentication settings are appropriate, and connection strings are accurate. Additionally, checking SQL Server logs and testing connectivity.