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From: Makey@Logicon.COM (Jeff Makey)
Newsgroups: comp.protocols.tcp-ip.domains
Subject: Re: Proposal for use of DNS to store RFC 987, etc mappings
Message-ID: <731@logicon.com>
Date: 27 Jul 90 21:27:59 GMT
References: <9007270026.AA16028@bel.isi.edu> <1990Jul27.145802.19330@chx400.switch.ch>
Distribution: inet
Organization: Logicon, Inc., San Diego, California
Lines: 56
X-Local-Date: 27 Jul 90 14:27:59 PDT

In article <1990Jul27.145802.19330@chx400.switch.ch> poole@chx400.switch.ch (Simon Poole) writes:
>Internet <-> X.400 mail system <-> local RFC822 mail system
>                                   (without DNS connectivity)

I have recently been thinking about a similar problem, which I suspect
is much more common:

    Internet <-> UUCP mail system <-> isolated internet

This problem is somewhat easier than the X.400 version because UUCP
uses RFC 822, but the isolated internet still has no direct access to
the Internet DNS (although it might run an isolated DNS for its local
domain).  The solution to both problems is conceptually simple:
provide a protocol that allows non-Internet sites to indirectly query
the Internet DNS.

Discussion thus far has concerned a proposed implementation of such a
protocol in which the entire Internet DNS would be transmitted to the
isolated network on a periodic basis.  Some other ideas I haven't seen
are:

 1) Regularly transmit different portions of the Internet DNS to the
    isolated network on a rotating schedule.  This is comparable to
    periodic transmission of the entire DNS, but spreads the
    transmission load more evenly over time.  The model for this is
    the use of USENET's comp.mail.maps newsgroup to distribute the
    UUCP Map.

 2) Transmit changes in the Internet DNS database to the isolated
    network as they occur.  Combined with the ability for new isolated
    networks to fetch the entire DNS, this seems to be a more
    efficient method than the above.

Perhaps one of the biggest problems with all of these ideas so far is
that there will be a copy of the *entire* Internet DNS per isolated
network, plus a copy maintained at each Internet site that provides
the DNS to an isolated network.  I realize that gigabyte storage is
pretty cheap these days, but who wants to do backups of all that data?

 3) Probably the best long-term solution -- particularly for
    resource-poor isolated sites -- would be a query/response protocol
    that allows an isolated resolver to obtain DNS information on an
    as-needed basis over the intermediate non-internet network.
    Something analogous to UDP/X.400 (or UDP/UUCP when appropriate)
    would do the trick.  The performance of the intermediate network
    would affect latency, but that's why timeout values are
    configurable.  The nifty side effect of this approach is that the
    protocol would be symmetrical, which means that Internet sites
    would able to query the isolated DNS, giving the the effect of the
    single global DNS envisioned in RFC 1034.

                           :: Jeff Makey

Department of Tautological Pleonasms and Superfluous Redundancies Department
    Disclaimer: All opinions are strictly those of the author.
    Internet: Makey@Logicon.COM    UUCP: {nosc,ucsd}!logicon.com!Makey