Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!purdue!decwrl!vixie
From: vixie@decwrl.dec.com (Paul Vixie)
Newsgroups: comp.mail.uucp
Subject: Re: active rerouting
Message-ID: <801@bacchus.dec.com>
Date: 9 Sep 88 07:14:11 GMT
References: <4740@b-tech.UUCP> <4747@b-tech.UUCP> <4748@b-tech.UUCP> <4753@b-tech.UUCP> <1426@ficc.uu.net>
Sender: vixie@decwrl.dec.com
Organization: DEC Western Research Lab
Lines: 34

In article <1426@ficc.uu.net> karl@ficc.uu.net (karl lehenbauer#) writes:

# If one's mail had its route autogenerated by pathalias/smail, then one
# shouldn't mind if another site reroutes it, right?  (assuming their maps are
# at least as up to date as yours) I mean, you've already implicitly said that
# you trust smail to do the routing for you.  

Nope.  Sorry, I know it sounds like a good idea but there's a missing link:
my paths database was generated with some extra glue and real data that is
not part of the published maps (nor should it be!).  I exert certain prefer-
ences and exploit certain private information when I build my paths database,
and I do not at all expect that anyone else will have the same preferences
or have access to the same information.

I tell pathalias to stay away from sites I know are having trouble this week.
I tell it to prefer a link between two remotes if I control both remotes and
know the reliability (and want to pay for that hop).  I tell it about links
between remotes that most people won't know about because they are for private
use only.

When my mail gets rerouted, all that is lost.

So, while it sounds like a good idea to be able to tell when a path was
generated by a machine and reroute it, in fact _any_ path that comes out
of a machine you don't control may (will!) have been generated from data
which you don't possess.  Or so you ought to assume.

I know you're new at this, and I hope you'll keep at it.  We need to get and
keep lots of good people thinking about problems like these and looking for
and finding better solutions than the ones presently in use.
-- 
Paul Vixie
Work:    vixie@decwrl.dec.com    decwrl!vixie    +1 415 853 6600
Play:    paul@vixie.sf.ca.us     vixie!paul      +1 415 864 7013