🚀 go-pugleaf

In article <KARL.89Jul14145852@giza.cis.ohio-state.edu> karl@giza.cis.ohio-state.edu (Karl Kleinpaste) writes:
 > My, I can feel it getting warmer in here already...
Don't worry, I have the breeze off the lake to keep me cool :-)

 > Passive rerouting, when the first specified host in the path is
 > unknown, is a violation of the source-route rules as much as active
 > rerouting.  If we're going to attach strict source route rules to
 > !-paths, then we have to obey those rules.  Those rules say that, if
 > you give me
 > 	<@a.b,@c.d,@e.f:u@g.h>
 > then I must hand the mail _directly_ to a.b.  It doesn't say that I
 > may find my own best intermediate-hop route to a.b; it says I have to
 > go straight there.
You are quite correct.  You should try to deliver the mail directly to a.b 
or else return a failure, WITH THE EXCEPTION OF AN MX RECORD.
However, this just means that your logic example [deleted for brevity] is
flawed because the conclusion is correct (not false) and thus the condition 
is still valid (correctness, we are still debating).

This means that if you receive a message to "b!c!d@a", after removing "a"
and rewriting using rfc976 (leaving you with "c!d@b"), you must be able
to reach site "b".

At this point you have three options.  All of which I feel are within
the rules.

Option one is to return an error message if you are unable to get to
site "b" directly via UUCP or SMTP.  This means that all our User Agents
(UA) must be made more intelligent.  The Mail Transport Agents (MTA)
should not try to do routing.  I do not know how well this would agree
with most people.

Option two is to return an error message if you are unable to get to
site "b" directly via UUCP or SMTP and "b" is part of a source route address
("c!d@b")[i.e. it is not a simple address "x@b"].  I think more people would
agree with this solution since so many of our UA's depend upon the MTA's
to have the smarts for routing simple addresses.  Whether this is "GOOD"
or not is another debate.

Option three is to say that it should try to deliver mail to site "b"
using the information available to it, treating pathalias data as
just another form of MX record.  When looking up a name via the
Domain Name Service (DNS) we accept an MX record to be the equivalent of
a host record for ALL mail purposes (including source routing).
What this option asks us to do is treat a pathalias record as the equivalent
of a host record for mail purposes.  Notice, this does not imply that we 
should short circuit (actively reroute) a source-route just because there 
is an MX (pathalias) record for a host.  It should still go to each host
along the route.

I hold option three to be the best way to go, but I can see the usefulness
of any of the three options.

Aydin Edguer		+1 216 368 6123		edguer@alpha.ces.cwru.edu
Department of Computer Engineering, Crawford Hall, Case Western Reserve Univ.