Subject: Re: DNSEXT WGLC AXFR-02 SHORT last call

From: Robert Elz <[email-masked]>
Date: Wed, 04 Jul 2001 05:00:50 -0700

Date:        Sat, 30 Jun 2001 10:07:14 -0700
    From:        Paul Vixie <[email-masked]>
    Message-ID:  <[email-masked]>

  | Robert, you were involved in the RFC 1996 discussions, both in the meetings
  | and here on the mailing list.

Yes.

  | You ought to remember that what was determined
  | (proposed by me and consensed by others) is that there is no such thing as a
  | "primary" vs "secondary" server.

Yes, but it isn't the words that matter, there is no such thing as a master
vs slave server either.   It is attempting to categorise the server that is
broken, not the words used to do it.

At some time or other I recall hearing words along the lines of "the use of
primary and secondary was based upon a misunderstanding of 1034/5" - at the
time I didn't recall what was in those docs accurately enough to dispute that
(that is, I knew the content, but the terminology used to describe it
could have been almost anything - though I certainly remembered at least
"master" being used there) so I couldn't dispute that at the time.

Later when I actually went and checked to see just where this misunderstanding
had come from, I found nothing to indicate any kind of misunderstanding at
all.   "Primary" and "secondary" was always right.  That is, using them
the way they were used derived from 1034/5 was correct -- 1034/5 themselves
could have used master/slave for the distinction, or other completely
different terms from any we're using today (in OSI speak they'd probably
have been zone transfer initiators and zone transfer responders or something,
and we'd talk of ZTIs and ZTRs...) but they didn't, the terms picked
initially were primary and secondary, and we create less confusion if we
simply stick to them.

  | The shorthand of "primary" used to mean "loads the zone content from outside
  | the DNS" but that's a meaningless distinction if DNS isn't used to copy zones
  | between the various authoritative servers for the zone.  All of them would be
  | primary in that case.

Yes, they would.  So?   Using your terminology, all of them are master.
The only difference between what you're saying and what I'm saying is the
word that is used.   But "primary" and "secondary" are used throughout
1034/5 for this purpose.   "master"/"slave" are not.   Hence they're new
invented terms that aren't required for anything, we already had
perfectly good terminology...

  | That and only that is why late model BIND calls zones "master" and "slave".
  | "Master" means load from disk.  "Slave" means load via AXFR/IXFR (and disk).

In earlier bind, "primary" meant "loads from disc" and "secondary" meant
"load via AXFR" (IXFR didn't exist then).  There never was a need for a
change (those labels always applied to a particular zone in the bind
config, not to the server as a whole).

All that was changed was a label, confusing people, and adding nothing at all.

  | I now wish I'd just called them "authority" zones and let the presence or
  | absence of a "masters { };" clause determine the masterness/slaveness type.

For bind yes, that would have been fine.   The redundancy helps detect
broken configurations though (better human interface).

For other specs we (sometimes) need a way to categorise the status of a
server for the zone however, so we do need terms.

  | "Master" and "slave" survived the terminology evaluation because they refer
  | to a useful distinction -- "which role do you take in AXFR/IXFR?"  Whereas
  | "Primary" and "secondary" did not survive because they refer to no useful
  | distinction.

Nonsense - master==primary and slave==secondary - all that altered was
the word being used.   There's no other distinction at all.

And none of this explains how we need the redundant combination
"primary master".

  | (You are, by the way, the last person in the IETF whom I would have expected
  | an argument ad hominem from.

Apologies if it seemed to be that way - that wasn't what I intended.
All I intended was to point out that the advocate for using these terms
has been you, all of this time.   It has not come from anywhere else.

kre

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---

From: Masataka Ohta <[email-masked]>
Date: Wed, 04 Jul 2001 15:32:43 -0700

kre;

>   | between the various authoritative servers for the zone.  All of them would be

The above statements by Paul should be interpreted that when DNS isn't
used to copy zones, NOTIFY, RFC1996 and DYNUPD are meaningless.

> the word being used.   There's no other distinction at all.

Wrong.

There seems to be a lot of confusion.

What Paul ignored is that there may be zone transfer between secondaries,
even though he was warned so when he was writing RFC1996.

A secondary name server may behave both as "master" and "slave" (a
better terminology is "server" and "client" of RFC1995).

> And none of this explains how we need the redundant combination

We don't need it.

Paul just put it in RFC1996 without answering the counter arguments.

As a secondary name server may behave both as "master" and "slave", a
combination of "master slave server" would make more sense (than negative
infinity).

							Masataka Ohta