You can configure an instance of SQL Server to use either static or dynamic ports.
The following documentation should also be reviewed: Verifying the Configuration of SQL Server Ports and SQL Server Locks.
Configuring a static port
To configure an instance of SQL Server to use a static port
Start the Server Network Utility by doing one of the following:
Click Start > Programs > Microsoft SQL Server > Server Network Utility. Click Start > Run. In the Open box, type svrnetcn.exe, and then click OK.
The SQL Server Network Utility dialog box appears.
In the SQL Server Network Utility dialog box, click the General tab.
In the Instance(s) on this server list, select your instance of SQL Server.
If the TCP/IP protocol is disabled, enable it by clicking TCP/IP in the Disabled Protocols list box, and then clicking Enable.
In the Enabled Protocols list box, click TCP/IP, and then click Properties.
If TCP/IP protocol is disabled, enable it by clicking TCP/IP in the Disabled Protocols list box, and then clicking Enable.
In the Default port box, type a number for the static port and then click OK.
The static port that you specify must not be the same as the dynamic port on which your instance of SQL Server is currently listening. For example, if your instance of SQL Server is currently listening on dynamic TCP/IP port 1400, type 1500 for the new static port.
The static port that you specify must not be the same as the dynamic port on which your instance of SQL Server is currently listening. For example, if your instance of SQL Server is currently listening on dynamic TCP/IP port 1400, type 1500 for the new static port.
Click OK twice.
Restart the instance of SQL Server.
View the SQL Server error logs to verify whether or not the instance of SQL Server is currently using the static port.
Configuring a dynamic port
To configure your instance of SQL Server to use a dynamic port:
Start the Server Network Utility by doing one of the following:
Click Start > Programs > Microsoft SQL Server > Server Network Utility. Click Start > Run. In the Open box, type svrnetcn.exe, and then click OK.
In the SQL Server Network Utility dialog box, click the General tab.
In the Instance(s) on this server list, select your instance of SQL Server
If the TCP/IP protocol is disabled, enable it by clicking TCP/IP in the Disabled Protocols list box, and then clicking Enable.
In the Enabled Protocols list box, click TCP/IP, then click Properties.
If TCP/IP protocol is disabled, enable it by clicking TCP/IP in the Disabled Protocols list box, and then clicking Enable.
Type 0 in the Default port box, and then click OK.
Click OK twice.
Restart the instance of SQL Server.
View the SQL Server error logs to verify whether the instance of SQL Server is currently using the dynamic port.
If you have a clustered instance of SQL Server, and you follow the specified steps on a cluster node, you may notice that the TCPDynamicPorts and TCPPort registry values on other cluster nodes retain the old values. When you move the SQL Server group to the corresponding cluster node, and then bring SQL Server online on the cluster node, the registry values on the cluster nodes will reflect the updated values.