Originally posted by abhaysk
Thas fine but here it was IPC vs TCP..
Right. But you said "... if you give connect string while connecting to a DB then Oracle/OS is bound to use TCP", which certanly is not true, regardles of the initial question.

Nevertheless, if you want to stick with the original question, how about:
Code:
(ADDRESS = (PROTOCOL = IPC)(KEY = MY_IPC))
Why do you think this wouldn't work with the databse links? Original poster explicitely mentioned all instances to be addressed via db links are on the same server, so what's wrong with using IPC for db links?