How to: Connect to SQL Server Through a Proxy Server (SQL Server Configuration Manager)
To listen remotely by way of Remote WinSock (RWS), define the local address table (LAT) for the proxy server so that the listening node address is outside the range of LAT entries.
To enable connections to SQL Server through Microsoft Proxy Server
Follow the steps in How to: Configure a Server to Listen on a Specific TCP Port (SQL Server Configuration Manager) to determine which TCP/IP ports are used by the Database Engine, or to configure the Database Engine to use a desired port.
In your proxy server define the local address table (LAT) for the proxy server so that the listening node address is outside the range of LAT entries. For more information, see your proxy server documentation.