Net8

Net8, short for Oracle Net8, is Oracle Corporation's networking software that provides connectivity between Oracle clients and servers across a network. It is the networking layer of Oracle's database products and relies on the Transparent Network Substrate (TNS) to transport Oracle protocol messages. Net8 supports multiple components and configurations that enable applications to reach a database service across diverse environments.

On the server side, the Oracle Net Listener accepts client connections, forwards them to the appropriate database service, and manages sessions. On the client side, the Net8 client library builds and interprets network descriptors used to locate a database service. Connectivity is configured with files such as LISTENER.ORA on the server and TNSNAMES.ORA or other naming methods on the client. Net8 can also work with naming services to map logical names to network addresses.

Naming and connectivity: Applications connect using a descriptor that specifies host, port, and service name, or via naming methods such as TNS alias (defined in TNSNAMES.ORA), Easy Connect (a simplified host:port/service_name form), or directory naming via Oracle Names. Net8 supports multiple network protocols, with TCP/IP as the predominant transport, and it provides a level of abstraction that allows changes in network infrastructure without altering application code.

History and evolution: Net8 was introduced in the late 1990s as part of Oracle's shift from SQL*Net to a more flexible, naming-aware stack. It later evolved into Oracle Net, and by the 10g era was called Oracle Net Services; modern Oracle databases continue to use Oracle Net Services, though it is commonly referred to as Oracle Net.