Domain names play a key role in many NIS+ commands and operations. To avoid confusion, you must remember that, except for root servers, all NIS+ masters and replicas are clients of the domain above the domain that they serve. If you make the mistake of treating a server or replica as if it were a client of the domain that it serves, you may get Generic system error or Possible loop detected in namespace directoryname:domainname error messages.
For example, the machine altair might be a client of the subdoc.doc.com. domain. If the master server of the subdoc.doc.com. subdomain is the machine sirius, then sirius is a client of the doc.com. domain. When using, specifying, or changing domains, remember these rules to avoid confusion:
Client machines belong to a given domain or subdomain.
Servers and replicas that serve a given subdomain are clients of the domain above the domain they are serving.
The only exception to Rule 2 is that the root master server and root replica servers are clients of the same domain that they serve. In other words, the root master and root replicas are all clients of the root domain.
Thus, in the example above, the fully qualified name of the altair machine is alladin.subdoc.doc.com. The fully qualified name of the sirius machine is sirius.doc.com. The name sirius.subdoc.doc.com. is wrong and will cause an error because sirius is a client of doc.com., not subdoc.doc.com.