Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!ukc!dcl-cs!aber-cs!pcg
From: pcg@aber-cs.UUCP (Piercarlo Grandi)
Newsgroups: comp.mail.sendmail
Subject: Re: Short-circuiting a route
Summary: Never short circuit a route -- the world is weirder than you can imagine
Keywords: sendmail, smail, domain names
Message-ID: <1039@aber-cs.UUCP>
Date: 29 Jun 89 11:20:52 GMT
Reply-To: pcg@cs.aber.ac.uk (Piercarlo Grandi)
Organization: Dept of CS, UCW Aberystwyth
	(Disclaimer: my statements are purely personal)
Lines: 32

In article <562@daitc.daitc.mil> generous@daitc.daitc.mil (Curtis Generous) writes:
    More and more, I'm seeing UUCP mail going through my host of the format:
    
    	uucp1!uucp2!uucp3!domain.name!user
    
    Since we have both Internet and UUCP connections, what's the best way to 
    handle this situtation if your host is capable of sending mail directly to 
    'domain.name'?

The best solution is to ensure that people generating such routes have up to
date maps, that show that you have direct internet links. Otherwise source
routes ought to be religiously observed. The *only* reasonable action on a
source route is to *add* to it, and *only* at its beginning.

    Or should it be done?

NO! Leave those routes alone. If you try to short circuit, you will find that
a lot of domainized names are NOT on the internet, or there are good reasons
to use a UUCP channel to get at them, etc... Altering a source route for
such cases may well create loops.

Let's repeat for the zillionth time that "a.b.c" is a *name*, and does not
imply *anything* on the connectivity of "a.b.c" to any network, e.g. the
internet (as it should be; that is why top level domains that are network
names, e.g. bitnet or uucp, are very much frowned upon).  Domainization is
only a scheme to generate reliably unique names, not to give routing hints;
these should be based on maps. And you should never try to second guess
somebody's else's maps...
-- 
Piercarlo "Peter" Grandi           | ARPA: pcg%cs.aber.ac.uk@nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcvax!ukc!aber-cs!pcg
Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk