Database Security over the Net

I am looking for ways to secure a database that is being used over the net. I'm new to this topic and need recommendations on where to start. In terms of getting to a database on the "clean" side of a server, is there any settings in the TNSNAMES.ora that allows you to get to the "dirty" side then loop to the "clean side" ?

Thanks,
Frank Received on Thu Apr 13 2000 - 00:00:00 CDT