On Wed, 19 Feb 2003 Mark.Andrews@isc.org wrote: > > 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. 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. The contents could be given to the secondary by FTP or other method. If you mean to change the definition of zone contents, then I would say this proposal is hugely mis-labeled. 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.) 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. 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. > > 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. "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. 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. These unnecessary constraints are a "bad thing". > > 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. I presume agreement on the name change? --Dean
