Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!sharkey!emv
From: emv@a.cc.umich.edu (Ed Vielmetti)
Newsgroups: comp.mail.uucp
Subject: Re: uunet vs uunet.uu.net (was Re: how many "pluto"'s )
Message-ID: <986@mailgw.cc.umich.edu>
Date: 12 Oct 88 22:38:28 GMT
References: <731@mailrus.cc.umich.edu> <248@acheron.UUCP> <2521@epimass.EPI.COM> <734@mailrus.cc.umich.edu> <4788@b-tech.UUCP> <736@mailrus.cc.umich.edu> <4790@b-tech.UUCP> <10358@s.ms.uky.edu>
Reply-To: emv@starbarlounge.cc.umich.edu (Ed Vielmetti)
Organization: University of Michigan Computing Center, Ann Arbor
Lines: 37


Look at David Herron's article for context.

The only reasonable way I can think of to deal with switching from
using SMTP to using UUCP in reaching uunet (or uunet.uu.net) is
to change the sendmail.cf file once a day and flush out all of
the undelivered SMTP stuff via UUCP.  Once you've committed to 
UUCP delivery you're stuck, but if there's stuff queued up for
uunet.uu.net and it's undeliverable, just pop in a new config
file.

I'd save that for dire circumstances, and it's a non-trivial
change.

Oh, but here's another way of dealing with the problem: if there's
a list of 5 MX sites for a host, let's say, then you could have the
MX 0 point to the host, the MX 10 attempt to reach the machine
via SMTP, the MX 20 try to reach the destination via UUCP, and
MX 30 and 40 just attempt delivery.  That might be a reasonable
setup if the network looks like this:

	===fast internet==== -G- -slow line- -G- ===fast internet===
          40   30         20                      10    0
                           \---dial-up uucp------------/

If the network is up, the MX records will attempt direct delivery;
if the network is down, people on the "outside" will deliver to
the MX 20 host which will bypass the routing outage.

This won't handle the 'uunet' problem, though it's possible
at least in theory to do.  I'd imagine it's more likely to 
be used for corporate setups where there's a slow slip line
in and a friendly host on the other side.  

--Ed
(isn't routing fun?  it's easy if you can run just pathalias,
or just use MX records, but on the edges it gets trickier.)