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Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!down!honey
From: honey@down.FUN (Peter Honeyman)
Newsgroups: net.mail
Subject: Re: Name space explosion -- first tremors
Message-ID: <550@down.FUN>
Date: Thu, 1-Aug-85 22:14:43 EDT
Article-I.D.: down.550
Posted: Thu Aug  1 22:14:43 1985
Date-Received: Sat, 3-Aug-85 05:29:02 EDT
References: <9512@ucbvax.ARPA>
Organization: CS Dept., Princeton University
Lines: 42

jordan states that a host may be a member of more than one domain.
possibly he is referring to the following passage from rfc819:

   In reality, anomalies may exist violating the in-tree model of naming
   hierarchy.  Overlapping domains imply multiple parentage, i.e., an
   entity of the naming hierarchy being a child of more than one domain.
   It is conceivable that ISI can be a member of the ARPA domain as well
   as a member of the USC domain (Figure 2).  Such a relation
   constitutes an anomaly to the rule of one-connectivity between any
   two points of a tree.  The common child and the sub-tree below it
   become descendants of both parent domains.

                                 U
                               / | \
                             /   .   \
                           .     .   ARPA
                         .       .     | \
                                USC    |   \
                                   \   |     .
                                     \ |       .
                                      ISI

                                Figure 2
                      Anomaly in the In-Tree Model

   Some issues resulting from multiple parentage are addressed in
   Appendix B.  The general implications of multiple parentage are a
   subject for further investigation.

on the other hand, rfc920, "Domain Requirements" states:

   The domain is part of the host name.  Thus if USC-ISIA.ARPA changes
   its domain affiliation to DDN.MIL to become USC-ISIA.DDN.MIL, it has
   changed its name.  This means that any previous references to
   USC-ISIA.ARPA are now out of date.  Such old references may include
   private host name to address tables, and any recorded information
   about mailboxes such as mailing lists, the headers of old messages,
   printed directories, and peoples' memories.

it appears to me that the issue was resolved in favor of domain uniqueness.

	peter