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Re: axfr-clarify's fraudulent claims of consensus

2003-02-19 00:04:27
Josh Littlefield writes:
RFC1034 clearly states that the answer section "carries RRs which
directly answer the query."  I don't see how anyone could conclude
that AXFR clients should look for zone RRs anywhere else.

There is overwhelming consensus that (in the absence of extended
behavior requested by the client) the AXFR _server_ must leave the
additional section and authority section empty. It must put the data
into the answer section. All existing servers work this way---and must
do so for interoperability.

There are several perfectly valid parsing strategies for the client.
In particular, my software uses the simple strategy

   while there are records left
      read a record

while BIND 9 uses the slightly more complicated strategy

   while there are records left in the answer section
      read a record

Both strategies work, since servers put all records into the answer
section. Neither strategy creates any interoperability problems.

There is certainly _not_ consensus on telling the _client_ to use the
BIND 9 strategy. Furthermore, any such statement (whether ``MUST'' or
``SHOULD'') would blatantly violate RFC 2119, section 6.

This is about the tenth time that I have had to point out the blazingly
obvious fact that constraining _server_ behavior is not the same as
constraining _client_ behavior.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago