FNS uses six new maps which are stored in /var/yp/domainname directories on the NIS master and slave servers:
fns_host.ctx which stores user attributes and subcontext data. When this is first created, it derives its information from the passwd.byname map.
fns_user.attr which stores user attributes for attribute based searches.
Service and file context information for hosts, users, and the organization are stored in the respective fns_host.ctx, fns_user.ctx, and fns_org.ctx maps. Printer context information is stored in the same maps as other service context information. However, the older printers.conf.byname map is still supported.
These FNS maps should not be edited directly. You modify or work with these maps by running the appropriate FNS commands such as fncreate, fndestroy, fnbind, fnunbind, fnrename, fnattr, fnlookup, and fnlist. These commands must be run on the NIS master server. You cannot run them on slave servers or client machines.