Oracle Universal Installer starts Oracle Net Configuration Assistant (NETCA) after the database software is installed. NETCA creates the Oracle Net Services profile, or the sqlnet.ora file.

In an Oracle Grid Infrastructure installation, the sqlnet.ora file is located in the Grid_home\network\admin directory by default.

For the local listener for the Oracle RAC database instance, the default location of the sqlnet.ora file is %ORACLE_HOME%\network\admin directory. In this directory there is a default sqlnet.ora file. Also, you can find a sample sqlnet.ora file in the subdirectory sample.

During installation of the Oracle RAC software, NETCA creates the following entries in the sqlnet.ora file, where %ORACLE_BASE% is the path to the Oracle base directory for the Oracle RAC installation:

NAMES.DIRECTORY_PATH=(TNSNAMES, EZCONNECT)
ADR_BASE =%ORACLE_BASE%

The AUTHENTICATION_SERVICES parameter (not shown in the above example) specifies the method by which users are authenticated for database access. The value NTS indicates that Microsoft Windows native authentication should be used to authorize access to the database. Oracle Databases that use Oracle Automatic Storage Management (Oracle ASM) and the databases that are managed by Oracle Grid infrastructure must use Windows native authentication, which is enabled by default.

The parameter NAMES.DIRECTORY_PATH specifies the priority order of the naming methods to use to resolve connect identifiers to connect descriptors. The ADR_BASE parameter specifies the base directory into which tracing and logging incidents are stored when Automatic Diagnostic Repository (ADR) is enabled for the database.