Stefan - thank you for the information; I'll try your suggestion about bouncing the database to see if that gets the database links to work when the tnsnames.ora contains an ifile. Niall - did you just suggest that Tom Kyte was *gasp* wrong?!? Perhaps the E-business suite is using an unsupported feature of Oracle - "we'll use it ourselves because we know the gotchas but we won't let you, the customer, play around with it on your own." Does the E-business documentation actually tell the customer to set up a common network configuration file using ifile? Or do they install one on your machine but leave it unmentioned in the documentation? Thomas Mercadante - I agree with you that it's a pain to have to go digging through several files when you find a configuration file with an "ifile" parameter. But, for example, what if you have several oracle homes on the same machine, and want to make sure that all SQL*Net or listener log and trace files end up in the same directory? What I do is put the DIRECTORY parameter in a common file (pulled in through an ifile) and give each log / trace file a name that is version specific in the individual sqlnet.ora file for each version. Or for example the specification of the names server can be in the common sqlnet.ora file. That seems to me "simple and clear" - some changes only need to be made in one location. As far as tnsnames.ora goes, setting up a names server or an LDAP server is probably best practice - I do that here. But in the old days before names servers the ifile = in your tnsnames.ora file was the way to go. Old habits die hard.