Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!mstar!mstar.morningstar.com!bob
From: bob@MorningStar.Com (Bob Sutterfield)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: in-addr.arpa used?
Message-ID: <BOB.90Oct9175258@volitans.MorningStar.Com>
Date: 9 Oct 90 21:53:06 GMT
References: <9010091715.AA05649@ucbvax.Berkeley.EDU>
Sender: usenet@MorningStar.COM (USENET Administrator)
Reply-To: bob@MorningStar.Com (Bob Sutterfield)
Organization: Morning Star Technologies
Lines: 23
In-Reply-To: PIRARD%vm1.ulg.ac.be@CUNYVM.CUNY.EDU's message of 9 Oct 90 14:54:01 GMT

In article <9010091715.AA05649@ucbvax.Berkeley.EDU> PIRARD%vm1.ulg.ac.be@CUNYVM.CUNY.EDU (Andr'e PIRARD) writes:
   ...how useful is it to ask our administrators to implement their
   in-addr.arpa domains?  Is it usually done?

See RFC1123 ("Requirements for Internet Hosts -- Application and
Support"), section 6.1.1:

         Every host MUST implement a resolver for the Domain Name
         System (DNS), and it MUST implement a mechanism using this
         DNS resolver to convert host names to IP addresses and
         vice-versa [DNS:1, DNS:2].

Yes, it's very useful.  It's usually done.  Addresses for which
reverse mapping is not maintained are not in conformance to the
applicable standards, and should receive a firm finger-wagging.  If
your local administrators hesitate, bash them over the head with a
printed copy of RFC1123, all 98 pages.

Hmmm, I just noticed upon closer reading that this requirement only
applies to the resolver that must be available on each host.  It
doesn't say that an authoritative reverse mapping must be available
(from some name server somewhere) for every address.  So bash them
gently, if you must :-)