I installed NIS on a Sparcgate Master machine using apt-get install nis and adding to /etc/passwd and /etc/group a line +:::::: using a command like echo "+::::::" >> /etc/passwd.
/etc/init.d/nis was changed to say server there, and other miscellaneous things were changed. It is important to do make in /var/yp/ whenever a user is added, or the change will not take effect.
First, added to /etc/passwd and /etc/group a line like +::::::, then installed NIS on other machines with apt-get install nis. This way, NIS works immediately, without any tweaking up or doing /etc/init.d/nis restart
When installing nis, I could not do apt-get install nis since this version of apt-get did not work on a slink system. Then, when it was doing /etc/init.d/nis to start up the daemon, the startup process did not finish, died. This meant that on rebooting the machine it machine never came back trying to start NIS. This was a problem, and after starting up in single user mode with linux single, I did dpkg --purge nis.
I am now rather determined to upgrade to potato. However, it is quite difficult to do it on a machine which cannot usually be accessed physically, and which does not have a working version of apt.
It was a trivial task.
Now it is easy to add users, something else must be done. For every user, .rhosts should be added. Thus, I have added /etc/skel/.rhosts so that I don't need to bother to think about it anymore. It should be okay.