IXFR and AXFR

[Mark Andrews]

In message <20110127124124.5B8ED2D0E6 at mail.nsbeta.info>, pyh at mail.nsbeta.info writes:
> Mark Andrews writes: 
> 
> > The master will return a AXFR style IXFR whenever it doesn't have the requested a
> xfr stream.
> 
> Do you mean whenever it doesn't have the requested IXFR stream? 

When you make a IXFR request you say "please send me the changes starting at
this serial".  Sometimes the master will have already discarded some or all
of the changes.  IXFR allows for optional compression of deltas and if one of
the masters in the axfr graph does that and you have multiple masters listed
you make end up ask a master that about a serial that was compressed away.
 
> Thanks.
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org