[Pdns-users] Reverse DNS "delegation" - bug?

[Olly Butterfield]

Hi all

I'm running powerdns for reverse dns of a /19 block. We allocate smaller
blocks, a /24 or /25 for example, to customers and instead of delegating
reverse dns to their name servers at the level of RIPE, we just use pdns to
forward these queries to their nameservers. This is done by setting up NS
records for each reverse entry instead of PTRs. For example, aaa.bbb.ccc.ddd
points to server.ourcustomer.com.

So instead of doing...

Ddd.ccc.bbb.aaa.in-addr.arpa PTR server.ourcustomer.com

we do this instead....

Ddd.ccc.bbb.aaa.in-addr.arpa NS rdns-server.ourcustomer.com

And our customer has the PTR record set up.


This was working fine until a couple of days ago. We have 2 servers using
the same database through mysql replication. One has been upgraded to 2.9.19
from 2.9.17, the other is still running 2.9.17. Using dnsstuff.com to look
up a reverse record gives the following result when the server running the
OLD VERSION is queried.... (addresses have been changed)

###
How I am searching:
Asking f.root-servers.net for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:  
       f.root-servers.net says to go to sunic.sunet.se. (zone:
aaa.in-addr.arpa.)
Asking sunic.sunet.se. for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:  
       sunic.sunet.se [192.36.125.2] says to go to our.nameserver.net.
(zone: ccc.bbb.aaa.in-addr.arpa.)
Asking our.nameserver.net. for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:  
       our.nameserver.net [xxx.xxx.xxx.xxx] says to go to
customers.nameserver.net. (zone: ddd.ccc.bbb.aaa.in-addr.arpa.)
Asking customers.nameserver.net. for ddd.ccc.bbb.aaa.in-addr.arpa PTR
record:  Reports server.customer.com. [from yyy.yyy.yyy.yyy]
###

The above is correct and working with the old version of powerdns, however
if the server running 2.9.29 is queried, the following is returned...

###
How I am searching:
Asking g.root-servers.net for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:  
       g.root-servers.net says to go to sunic.sunet.se. (zone:
aaa.in-addr.arpa.)
Asking sunic.sunet.se. for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:  
       sunic.sunet.se [192.36.125.2] says to go to ourother.nameserver.net.
(zone: ccc.bbb.aaa.in-addr.arpa.)
Asking ourother.nameserver.net. for ddd.ccc.bbb.aaa.in-addr.arpa PTR record:
Got NODATA response type 2 [from zzz.zzz.zzz.zzz].
###

So the more recent version of powerdns isn't giving out the NS entries when
asked for the PTR, it's just not returning anything.

Any ideas anyone? Thanks for reading :)