Setting Up the Oracle Client

On the client computer from which you will connect:

Locate the SQLNET.ORA file in the directory where Oracle was installed. The file is located in ORACLE_HOME\Network\Admin directory under the main Oracle installation directory where ORACLE_HOME is the name assigned for the Oracle home during installation.
Open SQLNET.ORA and set the value of the following parameter as follows:
sqlnet.authentication_services = (NTS)

Note: Ensure this parameter is not commented out with a # at the beginning of the line. You may need to add this parameter.
Open the TNSNAMES.ORA file in the directory where Oracle was installed. This file is located in ORACLE_HOME\Network\Admin directory.

Copy the server’s database entry to the TNSNAMES.ORA file on the client computer. For example:

ORACLE_SID.DOMAIN.COM=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=TCP)(HOST=SERVERNAME)(PORT=1521))
)
(CONNECT_DATA=
(SERVICE_NAME=ORACLE_SID)
)
)