
There are at least three ways to set up NIS.

1. To use the files present in /etc.
2. To use files in a separate directory like this one. [Basically, one
needs to change the PWDIR line in /var/yp/Makefile to point to the
new directory.] In this case the passwd file can either be
2A. The SunOS 4.1.x passwd format without a shadow file or
2B. The Solaris 2.x passwd/shadow format.

We have used the 2A option here. Partly this was do to history. But
since the separate nis directory is not world readable, there is no
gain in going to the passwd/shadow dual file format.

The shadow format hides the encrypted passwds, but ypcat passwd exposes
them on any yp client. If you don't truss your users not to run crack
on the passwd file, this will not be secure enough. 
