If you block UDP port 1434 or TCP port 1433 on the computer that is running SQL Server, you must create a SQL Server client alias on all other computers in the server farm. You can use SQL Server client components to create a SQL Server client alias for computers that connect to SQL Server.
To configure a SQL Server client alias
- Verify that the user account that is performing this procedure is a member of either the sysadmin or the serveradmin fixed server role.
Run Setup for SQL Server on the target computer, and install the following client components:
- Open SQL Server Configuration Manager.
In the navigation pane, click SQL Native Client Configuration.
In the main window under Items, right-click Aliases, and select New Alias.
In the Alias – New dialog box, in the Alias Name field, enter a name for the alias. For example, enter SharePoint_alias.
In the Port No field, enter the port number for the database instance. For example, enter 40000. Make sure that the protocol is set to TCP/IP.
In the Server field, enter the name of the computer that is running SQL Server.
Click Apply, and then click OK.
Verification: You can test the SQL Server client alias by using SQL Server Management Studio, which is available when you install SQL Server client components.
Open SQL Server Management Studio.
When you are prompted to enter a server name, enter the name of the alias that you created, and then click Connect. If the connection is successful, SQL Server Management Studio is populated with objects that correspond to the remote database.
To check connectivity to additional database instances from SQL Server Management Studio, click Connect, and then click Database Engine.
See also :
Securing SharePoint: Harden SQL Server in SharePoint Environments
How to: Configure a Windows Firewall for Database Engine Access
How to: Configure a Server to Listen on a Specific TCP Port (SQL Server Configuration Manager)