3.1 Using Localized Management

When localized management is used, network computers are configured with configuration files. The files are stored locally on the computers.

Table 3-1 Oracle Net Configuration Files Used with Localized Management

Configuration File	Description
tnsnames.ora	Located primarily on the clients, this file contains network service names mapped to connect descriptors. This file is used for the local naming method.
sqlnet.ora	Located on client and database server computers, this file may include the following: Client domain to append to unqualified service names or network service names Order of naming methods the client should use when resolving a name Logging and tracing features to use Route of connections External naming parameters Oracle security parameters Database access control parameters
listener.ora	Located on the database server, this configuration file for the listener may include the following: Protocol addresses it is accepting connection requests on Database and nondatabase services it is listening for Control parameters used by the listener
cman.ora	Located on the computer where Oracle Connection Manager runs, this configuration file includes the following components: A listening endpoint Access control rule list Parameter list Each Oracle Connection Manager configuration is encapsulated within a single name-value (NV) string, which consists of the preceding components.

Typically, tools such as Oracle Database Configuration Assistant (DBCA) and Oracle Net Configuration Assistant (NETCA) create configuration files in the ORACLE_HOME/network/admin directory for Oracle Database installations, the GRID_HOME/network/admin directory for Oracle Grid Infrastructure installations, or the corresponding ORACLE_BASE_HOME/network/admin directory for a read-only Oracle home. If you have installed multiple databases, then these are created in the Oracle home or Grid home where DBCA or NETCA is run (or the Oracle base home for read-only instances). However, configuration files can be created in other directories.

For example, the order for checking the tnsnames.ora file is:

1. The directory specified by the TNS_ADMIN environment variable

2. If the TNS_ADMIN environment variable is not set or the file is not found in the TNS_ADMIN directory:

   • On Linux and UNIX: The ORACLE_HOME/network/admin directory (or its ORACLE_BASE_HOME/network/admin directory for a read-only Oracle home)

   • On Windows: ORACLE_HOME\network\admin directory (or its ORACLE_BASE_HOME\network\admin directory for a read-only Oracle home)

3. For a read-only Oracle home, if the file is not found in the Oracle base home:

   • On Linux and UNIX: The ORACLE_HOME/network/admin directory

   • On Windows: The ORACLE_HOME\network\admin directory

Note:

• On Windows, the ORACLE_HOME location is determined by the ORACLE_HOME\bin\oracle.key file (which contains the name of the Windows Registry key where ORACLE_HOME is defined). Also, the TNS_ADMIN environment variable is used if it is set in the environment of the process. If you do not define the TNS_ADMIN environment variable in the environment or if the process is a service that does not have an environment, then Windows scans the registry for a TNS_ADMIN parameter.

• With Oracle Instant Client, tnsnames.ora is located in the subdirectory of the Oracle Instant Client software. For example, in the /opt/oracle/instantclient_release_number/network/admin directory.