[Pdns-users] AXFR of ALIAS records pointing to records of same zone

[Andreas Pfohl]

Hello Oliver,

thanks for the answer. But I guess there is more to this, as I pointed out in this issue on GitHub: https://github.com/PowerDNS/pdns/issues/4655

Maybe I’m wrong on all this.

> Am 03.11.2016 um 15:02 schrieb Oliver Peter <lists at peter.de.com>:
> 
> Hi Andreas,
> 
> On Sun, Oct 30, 2016 at 09:34:54PM +0100, Andreas Pfohl wrote:
>> Hello,
>> 
>> I’m trying to build a setup where PowerDNS is used as a hidden primary DNS server. The job of this PowerDNS server is, to provide zone transfers to the OpenDNSSEC service for signing the zone data.
>> 
>> What I’m trying to achieve is the ability to use the new ALIAS record to merge data from records of the same zone. I have created the following records:
>> 
>> dyn.example.com.     A     127.0.0.1
>> service.example.com. AAAA  ::1
>> service.example.com. ALIAS dyn.example.com.
>> 
>> This works great so far. If I query for service.exmaple.com. I get both IP addresses back in the response.
>> 
>> Now, I change the A record to 127.0.0.2 in the database. The zone transfer which is caused by updating the record in the database delivers the AAAA record of ::1 and the A of 127.0.0.1, instead of ::1 and 127.0.0.2. I see, that there is some sort of race condition going on here.
> 
> "Some sort of race condition" might be your local resolver still
> serving the old result for dyn.example.com from it's cache; try to flush
> it from there after you made your database changes:
> 	$ sudo unbound-control flush_zone example.com
> 	ok removed 5 rrsets, 3 messages and 1 key entries

It is hardly possible to flush the zones in the resolver due to the fact, that PowerDNS is looking for zone changes in the database periodically. Thus, I don’t know when to flush the resolver. I also tried with a TTL of 0 seconds, which should turn off caching in the resolver. Still got the same results.

> 
> Cheers
> 
> 
> -- 
> Oliver PETER       oliver at gfuzz.de       0x456D688F

Andreas