Path: utzoo!attcan!uunet!husc6!mailrus!purdue!decwrl!hplabs!ucbvax!VENERA.ISI.EDU!pvm
From: pvm@VENERA.ISI.EDU (Paul Mockapetris)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Domain name/subnet non-relationship.
Message-ID: <8806292148.AA25642@venera.isi.edu>
Date: 29 Jun 88 21:48:17 GMT
References: <8806291504.AA11495@gaak.LCS.MIT.EDU>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 14

As many have pointed out there is no necessary correspondance between
the name of a host, mailbox, etc. and the subnet that the host's IP
address occupies.

However, in the IN-ADDR.ARPA domain, which is used to map from IP
addresses to host names, the name structure is constrained (by
convention, not technically), with each level of the name corresponding
to an octet of the IP address.  Since the names break at octet
boundaries, domains/zones can only break at octet boundaries, and thus
if you want to separately administer address assignment, its much
simpler if your subnet masks and octet boundaries correspond.  For class
C, this means you are out of luck.

paul