User Types and Credential Types

A user can have both types of credentials, but a machine can only have DES credentials.

Root cannot have NIS+ access, as root, to other machines because the root UID of every machine is always zero. If root (UID=0) of machine A tried to access machine B as root, that would conflict with machine B's already existing root (UID=0). Thus, a LOCAL credential doesn't make sense for a client workstation; so it is allowed only for a client user.