Restrict users to certain machines

[McClain, Luke]

Is there a way restrict users from accessing certain machines with their krb
account.
Before we implemented kerberos, the netgroups I set up with NIS were working
fine for this purpose. It seems
like kerberos completely ignores my netgoups now because users restricted
before via netgroups, now are able to login
with their kerberos account. Has anyone run into similar problems? what was
your fix.

Thanks in advance.
Luke McClain