Sun (at least in SunOS 4) didn't do any "mucking about" with libresolv and YP in libc. ypserv(e) is responsible for consulting the DNS, if the NIS maps (host.byname/byaddr) are setup with a special key/value pair. Things are different in Solaris. The resolv+ package shows exactly how to replace routines in the libc.so/sa files such that the gethostbyname()/gethostbyaddr() lookups happen via the DNS (or NIS, or just the /etc/host file, it depends on how you configure things). Similar things could be done for any routine in libc, or any other shared library, for that matter. [Unfortunately, 'rcp' and everything in /sbin (SunOS 4 again) are staticly linked, so if 'rcp' is important to you and you want to use the resolv+ functionality, you'll have to find the BSD source and build a copy for yourself.] Replacing ruserok() and friends should be trivial. Jim