Specify UID and GID for Anonymous NFS Connections

Description

To specify the UID and GID for remote root users, edit the /etc/exports file and add the following for each export:

anonuid=value greater than UID_MAX from /etc/login.defs
anongid=value greater than GID_MAX from /etc/login.defs

Note that a value of "-1" is technically acceptable as this will randomize the anonuid and anongid values on a Red Hat Enterprise Linux based NFS server. While acceptable from a security perspective, a value of -1 may cause interoperability issues, particularly with Red Hat Enterprise Linux 7 client systems. Alternatively, functionally equivalent values of 60001, 65534, 65535 may be used.

Rationale

Specifying the anonymous UID and GID ensures that the remote root user is mapped to a local account which has no permissions on the system.