[Pdns-users] Why does pdns-recursor fail to resolve: data.public.lu

[Pieter Lexis]

Hi Sjors,

Please keep the mailing-list in the 'To' field so others can see your
emails as well.

On 7/12/21 2:05 PM, Sjon Hortensius wrote:

> this is using PowerDNS Recursor 4.5.2 on archlinux, my configuration is
> pretty plain:
> 
>> export-etc-hosts=on
>> local-address=::1
>> query-local-address=::

The last option is your problem. You're _only_ using IPv6 to contact
other nameservers. Here's what happens:

We've found the nameservers for public.lu via .lu:
Jul 12 15:14:44 [1] data.public.lu: got NS record 'public.lu' ->
'ns1.etat.lu.'
Jul 12 15:14:44 [1] data.public.lu: got NS record 'public.lu' ->
'ns2.etat.lu.'
Jul 12 15:14:44 [1] data.public.lu: got NS record 'public.lu' ->
'ns3.etat.lu.'

And get the glue addresses for those nameservers from the .lu servers:
Jul 12 15:14:44 [1]     ns3.etat.lu: accept answer
'etat.lu|NS|ns1.etat.lu.' from 'lu' nameservers? ttl=43200, place=2 YES!
Jul 12 15:14:44 [1]     ns3.etat.lu: accept answer
'etat.lu|NS|ns2.etat.lu.' from 'lu' nameservers? ttl=43200, place=2 YES!
Jul 12 15:14:44 [1]     ns3.etat.lu: accept answer
'etat.lu|NS|ns3.etat.lu.' from 'lu' nameservers? ttl=43200, place=2 YES!

However, those are only IPv4 addresses. We can't reach those to because
you've disabled outgoing IPv4. Hence, there are no addresses for us to
contact (although we try to get the AAAA records, but there simply are
none).

I can **highly** recommend turning on IPv4 outgoing in addition to IPv6
with query-local-address=::,0.0.0.0. IPv6-only resolving simply does not
work on the current internet.

> Would upgrading to 4.5.4 fix this?

No, this will never work until those nameservers get IPv6 addresses (and
AAAA glue).

Cheers,

Pieter

-- 
Pieter Lexis
PowerDNS.COM BV -- https://www.powerdns.com