The TNSNAMES.ORA file contains configuration information for Oracle database connectivity. It is used by many tools. The Oracle client, Discoverer, Toad, SQLNavigator are but a few. Information Warehouse also uses this.
The default location for the file varies per Operating System. A Windows search for *.ora will locate existing ORA files.
Some default locations include:
SQLNET.ORA can also contain configuration data. UVa Oracle implementation does not utilize SQLNET.ORA. If it exists, Oracle will try to use it and this may cause connectivity failure. Most users will want to delete or rename SQLNET.ORA files.
Click on the link below to download the file. (One may have to Right-click on the link, depending on browsers and settings.)
Download Tnsnames.ora Updated 07/01/2014.
Warning: Be sure that you save the file as tnsnames.ora. If your computer does not display file extensions, it is possible that the file will have an extension you are not aware of and will not work properly. For example, there have been cases where the file appeared to be named tnsnames.ora, but when the file extensions were turned on, the name was actually tnsnames.ora.txt.