Verifying the Configuration of SQL Server Ports

Verifying the configuration of a SQL Server port is a two-step process:

• Finding the TCP/IP port
• Verifying the configuration of the port

Finding the TCP/IP Port

To find the TCP/IP port of a SQL Server instance:

1. Start SQL Query Analyzer, and then connect to the SQL Server instance.
2. Run the following Transact-SQL statement in SQL Query Analyzer:

   Use master
   Go
   Xp_readerrorlog
   

3. In the Results pane, locate the following text:

   SQL server listening on X.X.X.X: Y
   

   Where X.X.X.X is the IP address of the SQL Server instance and Y is the TCP/IP port on which SQL Server is listening.

   For example, if SQL server is listening on 10.150.158.246: 1433, 10.150.158.246 is the IP address of the SQL Server and 1433 is the TCP/IP port on which the SQL Server instance is listening.

To verify the port configuration of a SQL Server instance:

1. Start the Windows Registry Editor.
2. In Registry Editor, locate the following registry key:

   HKEY_LOCAL_MACHINESOFTWAREMicrosoft
   Microsoft SQL Server
   MSSQLServerSuperSocketNetLibTcp
   

   The TCPDynamicPorts and TCPPort values appear as follows, depending on your port allocation method:

   • Static Port Allocation

     If you configure an instance of SQL Server to use a static port, and you have not yet restarted the SQL Server instance, the registry values are set as follows:

     TCPDynamicPorts = Last port used

     TCPPort = New static port that you set by using the Server Network Utility.

     If you configure an instance of SQL Server to use a static port, and you restart the SQL Server instance, the registry values are set as:

     TCPDynamicPorts = Blank

     TCPPort = New static port that you set by using the Server Network Utility.

   • Dynamic Port Allocation

     If you configure an instance of SQL Server to use dynamic port allocation, and you have not yet restarted the SQL Server instance, the registry values are set as follows:

     TCPDynamicPorts = Blank

     TCPPort = 0

     However, if you configure an instance of SQL Server to use dynamic port allocation, and you restart the SQL Server instance, the registry values are set as follows:

     TCPDynamicPorts = Current port used

     TCPPort = Current port used