Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!ukc!etive!glasgow!andrew
From: andrew@stl.stc.co.uk (Andrew Macpherson)
Newsgroups: comp.mail.sendmail,mail.uk-sendmail-workers
Subject: Re:  Another 2.1 concept error?
Message-ID: <8906131723.2565@stl.stc.co.uk>
Date: 13 Jun 89 17:23:08 GMT
Sender: daemon@cs.glasgow.ac.uk
Lines: 46
In-Reply-To: Message from "Steve Platt" of 13 Jun 89, 3:05 pm
Organisation: STC Technology, London Road, HARLOW, Essex England, CM17 9NA
Phone: 	+44 279 29531 ext 2423
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| >Shouldn't this order be changed?
| 
| Maybe, although it HAS matched a higher level name first;

Precicely, this is a mistake.

To be consistent with name-server operation, and the "domain names, concepts
and facilities" RFC, matching should be from local outward.

If you look at the resolver code (or set debug in nslookup) you will
see it try successively shorter parts pf your local domain before
submitting the "unadorned" string for a match.

The idea is to allow you to use a "short-form" to describe relatively
local entities, and only to require you to specify *from the point of
divergance with your local domain* for more distant.

Reversing this would be crazy.  If I wanted to call a machine
"uk.co.stc.stl.mod", [ ie "rocker"'s friend] I expect to be able to
refer to it as "mod", and not wind up with mail being sent to RSRE.
Simmilarly, if STC Telecoms had that machine, I would expect to specify
"tcom.mod"; this is where the UK sendmail has been "too nice" to the
users in the past... now that I am using the name-server code I can no
longer get away with the short-form in the non-local domains.  (All
addresses reversed to conform with NRS strangenesses)

| however, if I had a host/sub-department called "Acorn"
| I'd think twice before registering it in that name under
| the NRS.
| 
I'd be very tempted to register one of our hosts, just to make sure
everyone's software is resiliant  "uk.co.stc.icl.rbs.janet" :-)

| couldn't you elect to register
| as uk.ac.bristol.computer-vision (uk.ac.bris.cv)?
| 

[long and boring diatribe about excessively long and un-typeable
names suppressed]

-- 
-- 
Andrew Macpherson                          PSI%234237100122::andrew
andrew@stl.stc.co.uk        - or -         ...!mcvax!ukc!stl!andrew
"It is always a great mistake to treat the individual on the chance
that he may become a crowd" -- Mr Justice Codd: (A.P.Herbert)