Querying zone changes through IXFR.

[rjeffman]

dnspython makes it very easy to update a zone description through IXFR, but is there a way to be aware of only the changes made to a zone since a period in time (say since the previous SOA serial)?

[rthalley]

Can you give more detail on exactly what you want to do? Dnspython's inbound_xfr() code applies the whole zone transfer as a single transaction, so you can't currently look at the individual updates in the IXFR. Also, nameservers are allowed to compress changes in IXFRs or just give you an AXFR, so you can't reliably extract edit history from the authority. If you have a zone (e.g. from the last time you did an AXFR/IXFR) you can make a new version of the zone and then compare old and new. For example, if you had your existing zone state in a Versioned Zone you could use inbound_xfr() to get the latest version of the zone in a new version, and then use the transaction API and techniques like in examples/zonediff.py to compare old and new.

[rjeffman]

We need to be able to tell what changed in a zone that has been updated, for example, through nsupdate. I need to know what have changed in a zone to propagate this change to another sysem.

I wanted something like examples/zonediff.py, but I seem to have lost that example. And yes, I know that it might happend that IXFR turns into AXFR, so this example will probably be the best solution for my needs.