IXFR and AXFR

[Eivind Olsen]

> At what time the slave executes AXFR and at what time it executes IXFR
> from the master?

Someone please correct me if I give misleading information. I don't
believe I am, but I've been wrong before :D

There's a good section about this in the ARM, such as BIND 9.7 ARM section
4.3 - Incremental Zone Transfers (IXFR).

Basically, a BIND 9 slave will normally ask for IXFR unless told not to
(request-ixfr).
A BIND 9 master can't always provide IXFR though - if it can't it will
provide AXFR instead. To be able to provide IXFR it needs to have some
idea of the changes being made, so it can give a meaningful reply when
asked to provide "all changes since serial number X", so you'll normally
see IXFR being possible for dynamically updated zones (and a couple of
other cases, check the ARM).

Regards
Eivind Olsen