You can federate NIS+ or NIS to a global naming service like DNS and X.500.
To federate an NIS+ or NIS namespace under DNS or X.500, you first need to obtain the root reference for the NIS+ hierarchy or NIS domain.
From the point of view of the global name service, the root reference is known as the next naming system reference because it refers to the next naming system beneath the DNS domain or X.500 entry. To federate NIS+ or NIS with a global name service, you add the root reference information to that global service.
Once you have added the root reference information to the global service, clients outside of your NIS+ hierarchy or NIS domain can access and perform operations on the contexts in the NIS+ hierarchy or NIS domain. Foreign NIS+ clients access the hierarchy as unauthenticated NIS+ clients.
If NIS+ is federated underneath the DNS domain doc.com., you can now list the root of the NIS+ enterprise using the command
# fnlist .../doc.com/
If NIS+ is federated underneath the X.500 entry /c=us/o=doc, you can list the root of the NIS+ enterprise using the command:
# fnlist .../c=us/o=doc/
Note the mandatory trailing slash in both examples.