sqlnet Service

SunScreen contains an sqlnet state engine to screen Oracle SQL*Net protocol. SQL*Net is Oracle's remote data access protocol that enables client-server and server-server communications across networks.

An Oracle client connects to the server using the port address of the listener, which is normally defined as TCP port 1521 during Oracle installation. sqlnet service is defined as using TCP port 1521. If Oracle is installed using a different port for the listener, you can modify the service definition for sqlnet service accordingly.

SQL*Net connections are established in two ways. An Oracle client connects to the listener using TCP port 1521, and the connection is established with the listener process. With Oracle multithreaded servers and prespawned server processes, the client connects to the listener on TCP port 1521. The listener issues a redirect message back to the client containing an IP address and port number, and the client connects to this redirected IP address and port.

SunScreen supports both types of SQL*Net connections.