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From: gnu@hoptoad.uucp (John Gilmore)
Newsgroups: comp.mail.uucp
Subject: Re: dynamic routing for UUCP mail
Message-ID: <2707@hoptoad.uucp>
Date: Tue, 11-Aug-87 22:07:15 EDT
Article-I.D.: hoptoad.2707
Posted: Tue Aug 11 22:07:15 1987
Date-Received: Fri, 14-Aug-87 00:39:34 EDT
References: <915@bsu-cs.UUCP> <13680@topaz.rutgers.edu> <4577@felix.UUCP> <10149@orchid.waterloo.edu>
Distribution: na
Organization: Nebula Consultants in San Francisco
Lines: 23

There are two optimizations that we should be able to safely make for
rerouting bang-path mail.  (If I'm wrong, please post a polite correction.)

(1)	The uucp domain mail design was such that if a smart mailer
	finds a path like foo!bar!a.b.c!anything, and it knows how to
	get to a.b.c, it can throw away the foo!bar! part.  Furthermore,
	if there are multiple dotted addresses (e.g. foo!a.b.c!d.e.f!g),
	it can take the rightmost one it knows.  This is because domain
	addresses are UNIQUE by design.  (People who invent their own,
	and put them on mail, deserve what they get.)
	
(2)	I've been planning to put in a rerouter here that just shortens
	paths that go through sites ALL OF WHICH ARE KNOWN TO ME.  That's
	not to say that I have a link to them, but e.g.
		ptsfa!ames!ihnp4!cbosgd!ncoast!allbery
	can be cut down to ncoast!allbery because I have links to ptsfa,
	ihnp4, and cbosgd, and can add "ames" to a short list of sites
	that my neighbors talk to.  This relies on this small list of sites
	to not start passing data to a 3B2/1 called "ihnp4" somewhere in a
	small town in Oregon, but I think I can trust these guys.
-- 
{dasys1,ncoast,well,sun,ihnp4}!hoptoad!gnu	     gnu@postgres.berkeley.edu
My name's in the header where it belongs.