This document describe one of the most troblesome configuration I have ever set up.
It took me almost two days to figure out how to properly set everything to make it works so I'm writing this documentation to spare a headache to other sysadmins/DBA who wish to achieve the same.

I divided the process in three steps:
 

Connect Oracle to another DB

Generic Connectivity permits oracle to communicate and exchange data with other vendor databases such as DB2, Sql Server, MySQL, ecc.