Subject: Re: Bind 9 AXFR Modification vs AXFR Clarification

From: [email-masked]
Date: Wed, 19 Feb 2003 11:54:30 +1100

> Good. You found a bug in an implementation. I thought such things were
> off-topic for this list.  This bug doesn't mean that AXFR is broken.
> Bind 8 did not have this bug, yet it has the common understanding of AXFR.
> 
> Let me summarize the discussion:
> 
> Everyone agrees that AXFR specification in RFC 1034 is ambiguous.
> 
> Some people, many associated with Bind 9 development, assert that it is
> necessary to change AXFR to support IXFR.  This assertion has been refuted
> on the grounds that incremental database update does not depend on AXFR,
> since incremental database update does not depend on the underlying wire
> protocol used to create the remote database which is to be modified by
> IXFR. Conceivably, it is unnecessary to use AXFR at all, yet one could
> still use IXFR, so, AXFR is independent of IXFR.

	Nobody is saying that preserving zone content is a *wire*
	issue.  It is a server behaviour issue.

> Some people, many associated with Bind 9 development, assert that AXFR as
> commonly implemented by many implementors over many years, is broken, and
> can't transfer domains correctly.  This claim has been refuted by
> demonstration by interoperability between Bind 8 and other nameserver
> implementations over the years, and 77% of the internet that currently
> does not use Bind 9, yet still does AXFR.

	All this shows is that these nameservers are not used in
	situations where the breakage is demonstrated or the
	administators have learn to work around the breakage or
	choose to live with it or are unaware of it.

> There being no other arguments raised for the Bind 9 AXFR
> clarify/modification proposal, it seems that this proposal is gratuitous
> and unnecessary, and should be rejected.
>
> However, we still have the issue of AXFR ambiguity to deal with, and we
> still need to clarify those ambiguities.  I would therefore like to
> organize a small group of people using implementations other than Bind 9,
> which we declare to be broken, to document the common implementation
> assumptions made, and submit that as a clarification to RFC 1034
> 
> To prevent confusion between the two proposals, I would like to rename the
> first proposal "Bind 9 AXFR Modification", and the second proposal "AXFR
> Clarification". The term "axfr-clarify" will not be used.
> 
> 		--Dean
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]

---

From: Dean Anderson <[email-masked]>
Date: Wed, 19 Feb 2003 16:32:01 -0500 (EST)

On Wed, 19 Feb 2003 [email-masked] wrote:

> > All the IXFR server needs to do is determine (by some implementation
> > dependent, administrator maintained method) what has changed between one
> > zone version and another. How it does this is nobody's business but the
> > administrator and the implementor. There are infinite possibilities, here.
> > One could, for example, store differences in a series of files. The
> > administrator could even make the differnce files by hand--this is an
> > _implementation detail_. The IXFR server just sends a series or sequences
> > consisting of a list of deleted RRs and a list of added RRs to an IXFR
> > client. There is nothing more to it. (notwithstanding the optional
> > condensation.)
>
> 	All of which is irrelevent to this issue.

THAT's what I have been saying. You were the one who said we needed to do
this to support IXFR. I've been saying that claim was wrong. Thanks for
FINALLY coming round to that.

> > The IXFR client must simply make the changes (again, by some
> > implementation dependent, administrator maintained method) to the zone by
> > deleting RRs and adding RR's in each sequence. The original version of the
> > zone might have been obtained by FTP (or quantum interference, or the
> > psychic network) for all we know.
>
> 	Well the problem is that you have to get the *original* version,
> 	not a corrupted version.  AXFR implementations are not returning
> 	the data originally entered.

They sure have been.

> > This isn't rocket science, and doesn't require any AXFR changes. Nor does
> > it require that the zone boundaries be defined only in some certain way,
> > beyond the definition of zone boundaries given by the system
> > administrator.
>
> 	It does however require that for a given serial number that all
> 	sources of the zone have supplied identical contents.  You should
> 	be able to apply a IXFR delta to a copy derived from any source
> 	and have it apply without error.

None of this is relevant. All that is necessary is to delete the RRs, and
insert the RRs in the sequence.

If the zones are inconsistent through administrative mistake, then it
won't matter what the IXFR does.

> > "administrators have learn[ed] to work around [it,...] live with it [,] or
> > are unaware of it".  Agreed.  Having done so, we don't want to stir the
> > pot.
>
> 	LOL.

Strange, that was my reaction, too. I'm just trying to be polite.  77%
work just fine. We don't want to break 77% of the servers out there.

> > Essentially, you are putting more (unnecessary) constraints on
> > implementations, and thus on the administrators, who are supposed to be
> > pretty free to define the zone boundaries.  Of course, the specifics of an
> > implementation puts some constraints on the adminstrator, but the
> > administrator can choose a different implementation more to her liking.
>
> 	The constaint was already there and it is necessary for reliable
> 	operation of the DNS.

No, you ware not being honest about the contents of the Draft. See my last
message to Andreas.

> > I presume agreement on the name change?
>
> 	No.

Then the entire draft should be rejected since it is misleading.  Please
resubmit a proposal that isn't misleading the community about its purpose,
impact, and contents.

		--Dean

--
to unsubscribe send a message to [email-masked] with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/namedroppers/>

---

From: [email-masked]
Date: Thu, 20 Feb 2003 10:56:45 +1100

> > 	the data originally entered.

	Not always.
 
> won't matter what the IXFR does.

	Who said anything administrative mistakes?  The content is being
	unilaterally changed by the servers.
 
> work just fine. We don't want to break 77% of the servers out there.

	You really think that it will break those servers?  LOL.
 
> No, you ware not being honest about the contents of the Draft. See my last

	The abstract say:

				    This memo clarifies, updates, and
   adds missing detail to the original AXFR protocol specification in
   RFC1034.

	I fail to see how the contents can be deemed misleading when
	it states up front what it does.  Woops we missed warning you
	up front that it contains a warning.
 
> > > > > To prevent confusion between the two proposals, I would like to renam
> e th
> > > e

---

From: Dean Anderson <[email-masked]>
Date: Thu, 20 Feb 2003 11:32:38 -0500 (EST)

> > > 	the data originally entered.

You haven't shown any proof of that.  The "proof" you showed, was the
result of a misconfiguration.

> 	unilaterally changed by the servers.

It is reasonable and necessary to merge in glue. When you misconfigure the
glue, strange things may happen. That is all that you have shown.  I'm
sure that many software programs will exhibit even stranger behavior, and
may even fail to operate as a result of misconfiguration.

> 	You really think that it will break those servers?  LOL.

They will not be compliant, and thus will need to be changed. Thus, they
would be broken by definition of not being compliant.

Your failure to comprehend the consequences of the changes does not lessen
the effect.  We now agree that these changes aren't necessary to support
IXFR. You were part of the bad engineering that led to the unnecessary
creation of these changes in Bind 9.  You were also part of the bad
decision making that led to the distribution of these changes to Bind 9
users prior to standardization, and quite possibly you were part of the
bad decision making that resulted in publishing a book on the subject,
prior to acceptance of your modifications to standards. In short, you have
shown bad judgement.

Trying to "belittle" the effects with the "LOL", as opposed to offering
anything substantive, simply suggests that you have no appreciation of the
seriousness of the changes.  Perhaps you should take this more seriously.

> 	up front that it contains a warning.

I've no doubt that you fail to see it. We seem to be focusing a lot on
your failures. I have to question whether someone who went to MIT could
really fail so often. Perhaps it has changes since I was there. Or perhaps
you aren't really taking this very seriously. Let me explain it:

1) It doesn't say that it adds a completely new, incompatible zone
transfer protocol.  New protocols should be made through a different
process, which includes experimentation. I'm not against experimenting
with a new protocol. Indeed, I think this idea has some merit. However, it
can't be "end-run standardized" by a "clarification". There is a process.

2) It doesn't say that it changes AXFR with respect to SIG

3) It doesn't say that it changes the status of other RFC's (RFC 2845, and
possibly others.) without going through the appropriate standards process.

4) It doesn't say that it changes the definition of zone data to be
public. Zone data is absolutely not "public by definition". It could very
well be useful to tag certain RRs as non-public, and exclude them from
zone transfers to public servers. This "clarification" precludes that.
This is really 2 changes.

5) It doesn't say that it changes the security constraints on a zone
transfer to be limited to deny or accept only.

The list is longer, but that should be enough.

---

From: Dean Anderson <[email-masked]>
Date: Thu, 20 Feb 2003 21:19:51 -0500 (EST)

On Thu, 20 Feb 2003, Andreas Gustafsson wrote:

> Dean Anderson writes:
> > > > Zone definition and content is not an AXFR issue.  Server administrators
> > > > provide the definition of zone boundaries. (RFC 1034 Section 2.3 and
> > > > elsewhere)  AXFR merely gives the contents of the zone as has been defined
> > > > according to the boundaries and content specified by the administrator.
> > >
> > > This is exactly what the draft says, so what are you disagreeing with?
> >
> > Uhh, no. Draft 05 says quite a bit more.  It subtly changes a number of
> > things that shouldn't be, and don't need to be changed. In fact, looking
> > at my copy, it doesn't say anything like the above at all.  (But assuming
> > it did, it would be redundant and could be deleted).
>
> The draft says many things, and I understand that you are objecting to
> several of them, but we were specifically discussing zone boundaries,
> the subject of section 4.  Your statement that "server administrators
> provide the definition of zone boundaries" is consistent with the
> draft's existing wording and inconsistent with the BIND 4 / BIND 8
> handling of zone boundaries which you previously claimed to support.

Actually, I am quoting RFC 1034 directly. Section 2.3.

I believe you are misquoting the draft, since its section 4 doesn't say
anything like this.

Bind 8 will merge glue from child and parent zones. This merging is the
reason for the warning not to mix slave and master servers, since the
order of this merging is undetermined and the slave can overwrite the glue
originally supplied from the parent zone file.

> > Section 4 should be deleted.  Clearly, glue records need to be merged in.
>
> Are you saying section 4 should be deleted because you disagree with
> it, or because you find it obviously correct and therefore redundant?
> Also, which glue records need to be merged into what?

I disagree with it.  I gave several reasons in more detail in my last
message to Mark Andrews:

1) It makes it impossible to dynamically generate zones
2) It makes it impossible to give some data to public secondaries and
other data to private/trusted secondaries.
3) It offers no benefits.

The parent zone has glue records belonging to the child zone. It is quite
reasonable (perhaps not absolutely necessary) for those records to be
merged in as though the zone were spread across multiple files.

This is an administrative function of the server, on behalf of the human
adminstrator.

		--Dean

---

From: Dean Anderson <[email-masked]>
Date: Fri, 21 Feb 2003 00:25:56 -0500 (EST)

On Fri, 21 Feb 2003 [email-masked] wrote:

>
> > On Fri, 21 Feb 2003 [email-masked] wrote:
> >
> > > 	No.  It is the result of operational reality.  Whenever you
> > > 	have a parent and child zones under different administrative
> > > 	controls it is impossible to change both zones simultaniously.
> > > 	It is also impossible using AXFR or any other mechanism
> > > 	which transfers *individual* zones to transfer them to a
> > > 	secondary and guarantee that they will arrive simultaniously.
> > >
> > > 	Having parent and child zone under different administrative control
> > > 	is the norm not the execption.
> >
> > Actually, a parent always has some control over the child. It exercises
> > this control through the glue records.  When the glue records are in the
> > child zone, they need to be merged.
>
> 	Which is it.  Does the parent control the contents of its zone
> 	or does the child?

You seem not to understand the subtlety of the issue. The parent (like
real parents) ultimately controls the child, but the child (like real
children) has limited autonomy.

> > If a zone transfer happens while they
> > are inconsistent, it is possible for some strange results to happen.
> > Ordinarilly, zone transfers don't happen when they are inconsistent, since
> > the inconsistency is usually short.
>
> 	It doesn't matter if they normally happen while they are
> 	consistant.  You have to get correct behaviour while they
> 	are inconsistant.  Changing zone content on SECONDARY servers
> 	is not correct behaviour.

Sure it is. Unless you can arrange to conduct both updates simultaneosly.
While it would be possible to coordinate such changes on the phone,
relativity could come into play someday.  It has nothing to do with zone
transfers. Its part of the state of the system. Zone transfers is only one
way to learn about the state of the system.

> > Any zone transfers made during the inconsistent window are corrected so
> > long as the child zone is updated with correct information after the
> > parent is updated.
>
> 	This is a incorrect statement.

Could you elaborate?

> > Frequently the parent and child zone are under different administrative
> > control, and are frequently on different servers. In such a case, the
> > contents of the parent zone aren't merged with the child in the child's
> > server, and no evidence of the inconsistency is seen through zone
> > transfers. However, the inconsistency still exists and may still be
> > visible by resolvers and nameservers that lookup the glue records.
>
> 	Nobody is claiming that inconsistancies don't occur all the
> 	time.  What we are claiming is that those inconsistancies
> 	need to be preserved in SECONDARY servers for the correct
> 	operation of the DNS.  That they can only be corrected by
> 	modifying the PRIMARY source of the zones.

???  I can't parse this with respect to your previous statements. Could
you rephrase it?

During the period in which the zone is inconsistent, there is no guarantee
the zone will work.  Depending on the nature of the change, wrong
information may be given in queries as well. Suppose the parent is
removing control from the child, and has updated the glue to remove
referals to the child nameservers. For some time (the TTL, at least), the
original child servers will be queried.

On the other hand, the child zone may not even exist yet on the childs
nameservers.  Referals to the zone fail.

To make a concrete example, Osama registers alquaeda.com, and begins
coordinating his evil deeds. The registrar delegates the alquaeda.com as a
child of .com. Eventually, the government intervenes, and .com replaces
Osamas nameserver glue with new glue pointing to government servers. For a
time, this zone will be inconsistent. Note that in this case, the zone
transfers will not indicate the inconsistency.  However, for a short time,
Osama will be able to put up a message warning his followers not to go to
the government run site. This can't be avoided, no matter what gyrations
you put AXFR through.

It makes no difference that the inconsistency _could_, _in_some_cases_, be
seen at the secondaries.

> > You have obtained no benefits by these constraints.
>
> 	There are clear benefits in preserving zone contents on
> 	SECONDARY servers.

Such as?

Your term "preserving zone contents" is misleading. The zone contents are
not corrupted. The glue is inconsistent.  What is the benefit of
preventing any trace of inconsistency in the secondary?

It has nothing to do with IXFR. It has nothing to do with anything.

> > It is necessary, since the parent has glue records in the child zone.
> > The parent therefore has (always) a part of the child zone. If that server
> > also loads the child zone (or perhaps generates part of it dynamically),
> > it quite reasonable to merge the records as though the zone includes
> > multiple files, which in theory, it does.
>
> 	No it isn't.  Changes need to come from the PRIMARY source not
> 	from intermediate sources.

The intermediate sources aren't making changes. They are, at worst,
propogating old information mixed with new information. However, this is
visible in other ways besides zone transfers.

> > The child zone contents will only be correct when the administrators of
> > both zones agree on the contents of the glue records, and update their
> > parts of the child zone accordingly. It will not be correct until then,
> > regardless of how many zone transfers take place.
>
> 	Which is what I've been saying all along.  It doesn't require
> 	a server to "correct" the content at a intermediate point.  Such
> 	"corrections" actually cause problems.

Good. Then you agree that Bind 8 behavior is correct.

> > > 	Nothing in RFC 1033 / 1034 / 1035 says that a server is permitted
> > > 	to alter the content of a zone.  The responability for maintaining
> > > 	consistancy between zones is a administrative function.
> >
> > This is a loaded statement. The part of the server NOT involved in
> > responding to queries and zone transfers is part of the administrative
> > function. So, as part of that administrative function, it has to be able
> > to modify the RR and zones accordingly.  Your proposed changes exclude a
> > huge part of the potential for intelligence in name servers. And do so
> > with no benefits.
>
> 	The benefits are correct operation of the DNS regardless of the
> 	propogation timings involved.  If servers don't modify slave zone
> 	content then which the master servers are brought into sync all
> 	the servers will be brought into sync.

We already have correct operation of DNS. The zone contents are
inconsistent until both adminstrators come to agreement. The child zone
should be updated last. After the child zone is brought into agreement
with the parent glue, zone transfers will be made which are correct. Only
then will zone transfers will be correct.  Zone transfers made while the
administrators are not in agreement will not be correct, even if there is
no apparent evidence in the zone data from the child (such as a mixture of
new and old glue) they are still incorrect. NS Queries against the parent
and child servers will return different results.

> 	This is not guarenteed if the zone content is modified by a
> 	secondary server.
>
> > > 	So.  Just because they will not be compliant doesn't mean
> > > 	that that they need to be replaced immediately.  That
> > > 	non-compliance doesn't hurt most of them.  For those where
> > > 	it does have a negative impact it will mean that they should
> > > 	be able to request a fix from their vendor.
> >
> > You seem to make a case that in general, non-compliance doesn't hurt
> > anything. This is false, for both technical and commercial reasons.
> > Technically, it hurts interoperability, which has some many obvious harms
> > I won't go into them. Commercially, implementations make and advertise
> > compatibility and standards compliance claims. This retroactively makes
> > those claims false, which harms the business and reputation of those other
> > vendors.
>
> 	They will be harmed much more if they don't correct a common
> 	error now that it has been pointed out.

Except, there are no errors, beyond a window of inconsistency that cannot
be avoided, and in fact, that window isn't fixed. Nor do you fix the
"error". They are _still_ inconsistent for a period. And the child will
_still_ have to be updated last.

> 	The claims were made in good faith and will be accepted as
> 	such.

I'm not convinced.  If they were, we would have argued this before Bind 9
was released, and before a book was sent out. Probably about 3 years ago.
Someone knew years ago when they wrote the "backward compatibility" mode,
that they had a protocol issue that would have to come before
namedroppers.  That they delayed for so long doesn't indicate good faith
to me.

> > 77% will need a fix from the vendor, if we were to accept these changes.
> >
> > The vendor that made false claims of compatibility and standards
> > compliance is Bind 9. It should suffer the commercial damage to its
> > business and reputation, as a result.
>
> 	BIND 9 conforms to RFC 1034.  Nothing in RFC 1034 says to
> 	merge zone content.  If fact 1034 says that this a administrative
> 	responsability.

It does right now, due to a knowingly reckless exploitation of ambiguity
in the AXFR. Once AXFR is clarified, Bind 9 will have to use its 'backward
compatibility' mode to be compliant.

It is "knowingly reckless" because the Bind 9 implementers _KNEW_ they
needed to provide a "backward compatibility". That means they knew what
they were doing was incompatible with any (all actually) reasonable
interpretation (however ambiguous) of 1034.

> > > 	I never said that they we not necessary for IXFR.  I said that
> > > 	that your descripition of how to generate the differences was
> > > 	irrelevent to this discussion.
> >
> > Ok, you are half way there. They are irrelevant because IXFR is
> > irrelevant. These changes are not necessary to IXFR, as I explained that
> > IXFR can work with the current AXFR, or even without AXFR.
>
> 	IXFR cannot work through SECONDARY servers that change zone
> 	content regardless of whether the content was learnt via
> 	AXFR or IXFR.

Sure it can.  It doesn't need AXFR at all.  And the secondary's aren't
making arbitrary changes at all.

> > > 	It was bad engineering to merge the data sets together in the
> > > 	first place.  It was not required by RFC 1033/ 1034 / 1035.
> > > 	It had negative consequences.  It was good engineering to
> > > 	correct this.  It was also good engineering to report a
> > > 	common error to the community so that other vendors could
> > > 	fix their mistakes.
> >
> > Actually, since the parent has the glue in the child zone, it has part of
> > the child zone as well as the master zone.  Merging them together is not
> > prohibited, and in the case where child and parent have the same
> > adminstrator, as might be the case where most of the child is simply
> > automatically generated by the nameserver, can make things much easier.
> >
> > Your constraints preclude this unnecessarilly.
>
> 	The constraint in on the SECONDARY server.

So? It is still unnecesary.

> > Since I can think of cases where it is useful to merge records together,
> > it is bad engineering to remove that flexibility and obtain no benefits in
> > return.
> >
> > > 	I'm quite aware of what the change requires.  I'm also aware
> > > 	that most of the nameserver are used in situations where
> > > 	the zone contents is already preserved because they are not
> > > 	serving zones with parent / child relationships.
> >
> > Apparently, you aren't even aware that your changes will make all non-bind
> > 9 servers non-compliant.  Had you been aware of that, it seems you would
> > have brought this proposal forward something like 3 years ago, before
> > releasing Bind 9, and before publishing a book on the subject.
>
> 	Well you obviously have not been reading.  ISC is not the
> 	only vendor to come to the same conclusion about preserving
> 	zone content.  I suspect that they are just bored with
> 	arguing with you and Dan.

I think they just haven't really read the proposal's, and have taken some
misleading assurances at face value.

> > > 	Anyone saying that all the nameservers need to be replaced
> > > 	immediately is spreading FUD.  LOL the the correct reponse
> > > 	to FUD.
> >
> > Making 77% of the servers non-compliant is a fact of your proposed
> > changes.  It is another fact, as explained, that non-compliant servers
> > will need to be replaced.  Will they suddenly stop working? It depends on
> > whether other implementations want to implement a "backwards
> > compatibility" mode. If they don't implement this mode, then the answer is
> > yes, they will stop working as soon as these updates are deployed by other
> > vendors. Of course, this is a bad result.
>
> 	Well they havn't stopped working in the last two years that
> 	this code has been out there.  Nothing in this drafts stops
> 	a server implementing it taking to any other server.

Uhh, wrong. The drafts make the current AXFR non-compliant. There is
nothing that would require a server to implement the old AXFR and provide
a "backwards compatibility" mode such as Bind 9 has.

So servers running today, won't be able to talk to strictly compliant
servers that don't have a backwards compatibility mode.

> 	There is one backwards compatiblity switch which is only
> 	requires if you decide to send multiple records in a single
> 	messages.  A server is not required to send multiple records
> 	in a single message.

But is allowed to, and a server that can't receive such messages won't be
able to get the zone.

> > > 	It isn't new.  All it is saying is that the contents tramitted
> > > 	out MUST be that transmitted in.  This occurs most of the time
> > > 	already.  Note BIND is not the only implementation that does
> > > 	this.  We have already had reports of 3 other implementations
> > > 	doing this.  Even the implementations that don't guarentee the
> > > 	contents do this most of the time.  It has no negative effects.
> >
> > No, Section 3.1 is a whole new derivative of AXFR. That is new.
>
> 	Actually it's always been allowed by RFC 1034.  Just because
> 	it wasn't implement initially doesn't mean that it was not
> 	allowed.

Uhh, wrong, except in an unreasonably broad technical exception due to the
vagueness of 1034.

> > > 	Nowhere in RFC 1033 / 1034 / 1035 does it say that zone transfers
> > > 	are restricted to secondaries.  Nowhere in RFC 1033 / 1034 / 1035
> > > 	does it say that you should restrict zone tranfers.
> >
> > I don't think you understood my statement. I'm talking about the
> > definition of zone data. Nowhere does 1034 etc say that zone data is
> > public.  It may well have been thought to be public, originally, but since
> > I can easily see a useful purpose in withholding some private RRs, there
> > isn't any reason to preclude that behavior.
>
> 	Does this address your concerns?

No. Because it might be reasonable not to give complete zone data.

>    "The zone transfer protocol allows read-only access to the complete
>    zone data.  When the data being served to the public it is
>    generally acceptable to allow unrestricted access to it via AXFR.
>    Sites that wish to avoid disclosing their full zone data MAY
>    restrict zone transfer access to authorized slaves."
>
> 	If you have part of a zone to which you would normally
> 	return REFUSED to I suggest that you also return REFUSED
> 	to AXFR.
>
> 	If you want to be able to return partial zones then I suggest
> 	that a new TYPE be defined so that receipients can know
> 	that the results will be incomplete.

So far as the secondary is concerned, the zone is complete.  If you do
this, you don't want to tell people that you have some data that isn't
public.  Nor would you ever need to.

---

From: [email-masked]
Date: Fri, 21 Feb 2003 18:23:53 +1100

> children) has limited autonomy.

It is a subtle issue.  You can only apply changes to the PRIMARY source
of the data.  Applying changes at any other point has the potential to
cause servers to serve incorrect content.
 
> way to learn about the state of the system.

Changing the content of zones in SECONDARY servers prevents other SECONARY
servers using the first SECONDARY server learning the correct state of the
system.
 
> > 	This is a incorrect statement.

	Server A master to parent.
	Server B master to child.
	Server C slave to parent and child.
	Server D slave to parent using C as master.

	All servers with NS RRset N of child zone.

	Server B updates NS RRset to N'.
	Server A updates NS RRset to N'.
	Server C transfers parent from A.
	Server D transfers parent zone from C.
	Server C transfers child zone from B.

	End state with modification (BIND 8/tinydns).
	Server A N', Server B N', Server C N', Server D N.

	End state without modificatin (BIND 9).
	Server A N', Server B N', Server C N', Server D N'.

	You will notice that the last transfer above was the transfer of
	the child zone.
 
	Now lets update the child last.

	Server A updates NS RRset to N'.
	Server B updates NS RRset to N'.
	Server C transfers parent from A.
	Server D transfers parent zone from C.
	Server C transfers child zone from B.
	
	End state with modification (BIND 8/tinydns).
	Server A N', Server B N', Server C N', Server D N.

	End state without modificatin (BIND 9).
	Server A N', Server B N', Server C N', Server D N'.
	
	You will notice that the last transfer above was the transfer of
	the child zone.

	Lets wait for the parent zone to propogate to all servers
	before updating the child zone.

	Server A updates NS RRset to N'.
	Server C transfers parent from A.
	Server D transfers parent zone from C.
	Server B updates NS RRset to N'.
	Server C transfers child zone from B.

	End state with modification (BIND 8/tinydns).
	Server A N', Server B N', Server C N', Server D N.

	End state without modificatin (BIND 9).
	Server A N', Server B N', Server C N', Server D N'.

	Now if you force everyone to wait until the child zone
	has progated.

	Server B updates NS RRset to N'.
	Server C transfers child zone from B.
	Server A updates NS RRset to N'.
	Server C transfers parent from A.
	Server D transfers parent zone from C.
	
	End state with modification (BIND 8/tinydns).
	Server A N', Server B N', Server C N', Server D N'.

	End state without modificatin (BIND 9).
	Server A N', Server B N', Server C N', Server D N'.

	You will notice that in all examples BIND 9 ends in the correct
	state.  The same cannot be said for BIND 8 or tinydns.

	Modification of SECONDARY zone content is NOT required or desirable
	for the correct operation of the DNS.

> ???  I can't parse this with respect to your previous statements. Could

	You make changes at the PRIMARY server for the zone.
	You do not make changes to zones anywhere else.

> original child servers will be queried.

	What does this have to do with this draft?
 
> nameservers.  Referals to the zone fail.

	What does that have to do with this draft?
 
> the government run site. This can't be avoided, no matter what gyrations

	What has this got to do with this draft?
 
> It makes no difference that the inconsistency _could_, _in_some_cases_, be

	It does make a difference as demonstated above.
 
> preventing any trace of inconsistency in the secondary?

	It may be inconsistant but which version is correct?  The copy
	in the child may be out of date.
 
> It has nothing to do with IXFR. It has nothing to do with anything.

	IXFR still requires the content to only be changed in response
	to IXFR deltas.
 
> visible in other ways besides zone transfers.

	You are changing the contents if you mix data from different zones.
 
> Good. Then you agree that Bind 8 behavior is correct.

	BIND 8 "corrects" data at intermediate points.  BIND 9 doesn't.
	BIND 8's behaviour is wrong.
 
> and child servers will return different results.

	What have you been smoking?
 
> > > > > > > Strange, that was my reaction, too. I'm just trying to be polite.
>   77
> > > %

	You obviously don't understand the problem
 
> namedroppers.  That they delayed for so long doesn't indicate good faith

	We having been saying for years before BIND 9 was released that
	that BIND 8 had this wrong.  BIND 9 conforms to RFC 1034.

	Axfr-clarify arose because it was pointed out that IXFR depended
	upon the definition of AXFR and that AXFR was not well specified.

> compatibility' mode to be compliant.

	What "reckless" exploitation? 
 
> interpretation (however ambiguous) of 1034.

	The only thing that requires a backward compatability switch
	is sending multiple records in a message.

	BIND 4 accepted these back in 1996.  Other vendors started
	accepting these back in 1996.  BIND 8 has always accepted
	them and could be configured to send them.  BIND 9 defaults
	to sending them and can be configured not to.

	At the same time as this was happening other vendors also
	started sending them.  We all knew that there was interoprability
	issues that were a result of oversites in the implementation.
	One vendor even made use of the fact that named (and I
	presume other servers) didn't barf on a oversized query to
	signal to it servers that they could send a multi-record
	respones.
 
> > > > > Your failure to comprehend the consequences of the changes does not l
> esse
> > > n
> > > > > prior to acceptance of your modifications to standards. In short, you
>  hav
> > > e
> > > > > shown bad judgement.
> > > >

	If servers wern't making arbitary changes we would not be having
	this discussion.

> So? It is still unnecesary.

	Next you will tell me that the grass is blue and the sky is green.

	If you can't see the need for the constraint stop blocking those
	that do.

> > > > > anything substantive, simply suggests that you have no appreciation o
> f th
> > > e

	So you want

   "Slaves MUST accept messages containing any number of answer RRs.  For
   compatibility with old slaves, masters that support sending multiple
   answers per message SHOULD be configurable to revert to the
   historical mode of one answer per message, and the configuration
   SHOULD be settable on a per-slave basis."

	replaced with

   "Slaves MUST accept messages containing any number of answer RRs.  For
   compatibility with old slaves, masters that support sending multiple
   answers per message MUST be configurable to revert to the
   historical mode of one answer per message, and the configuration
   SHOULD be settable on a per-slave basis."

> > > > > with a new protocol. Indeed, I think this idea has some merit. Howeve
> r, i
> > > t

	Multiple records in the answer section have always been part
	of the standard.
 
> public.  Nor would you ever need to.

	Well if you don't want to tell them that you have private
	part then you won't be answering with REFUSED. You effectively
	have two zones that just have a lot in common.  Treat them
	as such.

	Mark

---

From: Matt Crawford <[email-masked]>
Date: Fri, 21 Feb 2003 12:09:08 -0600

> > draft-ietf-dnsext-axfr-clarify-00.txt                 Nominum Inc.
> >                                                         March 2000
> > Seems to be 3 years ago.
> I remember when people thought OSI protocols took too long to 
> standardize... :-)

"$X is a slow-moving parody of itself." -- Peter Honeyman

In the original, $X was bound to "USENET", not "IETF".