Topic Status: Some information in this topic is preview and subject to change in future releases. Preview information describes new features or changes to existing features in Microsoft SQL Server 2016 Community Technology Preview 2 (CTP2).


Product Name

SQL Server

Event ID


Event Source




Symbolic Name

Message Text

An error has occurred while establishing a connection to the server. When connecting to SQL Server, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 28 - Server doesn't support requested protocol) (Microsoft SQL Server, Error: -1)


The SQL Server client cannot connect to the server. This error could be caused by one of the following reasons:

  • A specified SQL Server instance name is not valid.

  • The TCP, or named pipes protocols are not enabled.

  • The firewall on the server has refused the connection.

  • The SQL Server Browser service (sqlbrowser) is not started.

User Action

To resolve this error, try one of the following actions:

  • Check the spelling of the SQL Server instance name that is specified in the connection string.

  • Use the SQL Server Configuration Manager tool to enable SQL Server to accept remote connections over the TCP or named pipes protocols. For more information about the accepting remote connections, see Enable or Disable a Server Network Protocol.

  • Make sure that you have configured the firewall on the server instance of SQL Server to open ports for SQL Server and the SQL Server Browser port (UDP 1434).

  • Make sure that the SQL Server Browser service is started on the server.

See Also


Network Protocols and Network Libraries


Configure a Windows Firewall for Database Engine Access

Configure Client Protocols

Configure Client Protocols

Enable or Disable a Server Network Protocol

Other Resources

Client Network Configuration