How can I make the NFS server ignore unprivileged clients?

In a restricted environment, i.e., an environment where the
administrator controls root access, you can enhance NFS security
by setting the "NFS_PORTMON" variable. This variable is set in
/etc/system, like this:

* Prior to Solaris 2.5
set nfs:nfs_portmon = 1

* Solaris 2.5 and later
set nfssrv:nfs_portmon = 1

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