NIS+ netgroups to control access

[Kristen J. McFadden]

Thanks to the people on this list I now have several RH 7.2 NIS+ clients (NIS+ server is solaris).  I am trying to restrict access to these machines differently from the other NIS+ machines.  

In other words, I want to only allow certain NIS+ users (e.g. group "redhat-users") to access these clients.

I have been told that netgroups can do it.  However, all the documentation I can find basically says to
make a netgroup called "redhat-users", then add the entry to the /etc/passwd that says "+ at redhat-users -----"

However, when I look at the /etc/passwd file on NIS+ clients, I actually see the entire access list.  It looks like
NIS+ now actually pushes the whole file over to the clients.  Therefore, I guess I have to do it entirely server side..
but how to differentiate between machines that I want everyone in NIS+ to use (ie. public unix box) vs. these special
redhat machines??

Any comments, suggestions, links, book recommendations?

Thank you kindly,
Kristen