[comp.mail.misc] !-path rerouting: One reason for doing so

karl@triceratops.cis.ohio-state.edu (Karl Kleinpaste) (03/19/88)

Although one would generally like to have !-paths left intact, there
is at least one circumstance wherein reroutes are entirely
appropriate.  When a site is set up to do replies using the Path:
header line due to not having INTERNET #defined, then reroutes may be
a necessary fact of life.

The reason is that not all host1!host2 connections that show up in the
Path: line are UUCP connections.  We speak NNTP with, e.g.,
mailrus.cc.umich.edu.  (Yes, Ohio State and Michigan can be civil
toward one another. :-)  So when we trade articles with them, the
Path: headers gain pseudo-UUCP connections that say
	tut.cis.ohio-state.edu!mailrus!some!where!username
and as we forward such an article farther down the line (via UUCP, for
example, through osu-cis and then to other Columbus sites), more sites
get tacked on the front of that.

Now someone replies to the !-path.  It says
	mumble!fubar!tut.cis.ohio-state.edu!mailrus!some!where!username
which hasn't got a chance of working.  We don't speak UUCP with
mailrus; we talk with them over our common NSF tributary.  So this
mail will do fine until it gets to tut.cis.ohio-state.edu, where we
will try to send mail via UUCP to mailrus - which will fail because
there is no `mailrus' in Tut's Systems file.  We don't reroute; we
just fail the mail and return it to where it came from, if possible.

This reflects not so much on the problems of !-path re-routing as it
does on the use of such an ambiguous syntax for the Path: header.  A
!-path `path' is not necessarily indicative of the transport used.

jbuck@epimass.EPI.COM (Joe Buck) (03/19/88)

In article <8563@tut.cis.ohio-state.edu> karl@triceratops.cis.ohio-state.edu (Karl Kleinpaste) writes:
>Although one would generally like to have !-paths left intact, there
>is at least one circumstance wherein reroutes are entirely
>appropriate.  When a site is set up to do replies using the Path:
>header line due to not having INTERNET #defined, then reroutes may be
>a necessary fact of life.

There is no longer a good reason not to define INTERNET, even for
sites with primitive mailers, when news 2.11 is used.

>The reason is that not all host1!host2 connections that show up in the
>Path: line are UUCP connections.

I have no problem with rerouting when the path is invalid, and the
rerouting is done to the first host, not the last.  a!b!c!user says
to send to a, then to b, then to c, then to user.  If a doesn't talk
directly to b, then a can route to b.  a should not attempt to route
directly to c in this case, though, since UUCP names can be ambiguous.
Now that we have the host.domain!user syntax, ! no longer implies
a direct UUCP connection.  But it is a route just the same.


-- 
- Joe Buck  {uunet,ucbvax,sun,<smart-site>}!epimass.epi.com!jbuck
	    Old Internet mailers: jbuck%epimass.epi.com@uunet.uu.net

jay@splut.UUCP (Jay Maynard) (03/26/88)

From article <2014@epimass.EPI.COM>, by jbuck@epimass.EPI.COM (Joe Buck):
> There is no longer a good reason not to define INTERNET, even for
> sites with primitive mailers, when news 2.11 is used.

Uh, Joe...if I define INTERNET, how do I keep news from trying
'mail buck@epimass.epi.com' if I reply to your message?
(If the answer is RTFM, please tell me where in the FM. :-)

One of these days, I'll figure out how to set up a useful subset of the
path database, and will get smail running...

-- 
Jay Maynard, EMT-P, K5ZC...>splut!< | GEnie: JAYMAYNARD  CI$: 71036,1603
uucp: {uunet!nuchat,academ!uhnix1,{ihnp4,bellcore,killer}!tness1}!splut!jay
Never ascribe to malice that which can adequately be explained by stupidity.
The opinions herein are shared by none of my cats, much less anyone else.

jbuck@epimass.EPI.COM (Joe Buck) (03/27/88)

In article <444@splut.UUCP> jay@splut.UUCP (Jay Maynard) writes:
>Uh, Joe...if I define INTERNET, how do I keep news from trying
>'mail buck@epimass.epi.com' if I reply to your message?
>(If the answer is RTFM, please tell me where in the FM. :-)

It's in there (in the 2.11 news installation guide).  Check out the
instructions on how to build the "mailpaths" file.  (There's also an
article posted every month to news.admin explaining the details).  

Say you have a plain UUCP mailer, but you talk to uunet.  Just
have the following line in /usr/lib/news/mailpaths:

internet	uunet!%s

Then a reply to my article will go to uunet!epimass.epi.com!jbuck
and will work fine.

The monthly article posted to news.admin gives the list of who
will accept internet mail from all comers.  In addition, if your
news feed has a full pathalias database running, you may be able
to obtain special permission to say

internet	news-feed!%s

But ask first!
-- 
- Joe Buck  {uunet,ucbvax,sun,<smart-site>}!epimass.epi.com!jbuck
	    Old Internet mailers: jbuck%epimass.epi.com@uunet.uu.net