[Pdns-users] How to set up pdns recursor to repeat the query if it does not get an answer

Mira Krejci krejci at i3.cz
Mon Sep 21 13:14:49 UTC 2020

Thanks Winfried and Brian for the anwers. This appears to be a PDNS
recursor property that cannot be configured by configuration.
I understand that repeated query is another burden for an overloaded
authoritative server, but an unsatisfied client will still query again.


Dne 18. 09. 20 v 17:42 Winfried Angele napsal(a):
> Hi Mira,
> I think if a Resolver retries on possibly overloaded or attacked
> authoritative DNS servers, it gets even worse for them. So I'd
> recommend to try to contact the people in charge for that domain and
> try to convince them to solve the problem on their side. And again,
> the Recursor tries on each Nameservers address listed in the NS RRset.
> So it does retries, but not on the same address. That means, in your
> case, all DNS servers of that domain are overloaded or broken or attacked.
> Winfried
> Am 18. September 2020 16:05:04 MESZ schrieb Mira Krejci <krejci at i3.cz>:
>     Hi Winfried,
>     thank you for your reply.
>     If it's a feature and can't be changed, I have a big problem that
>     I'll have to solve by changing the software to another.
>     For example, Bind asks more than once if answer does not come.
>     Users are angry that DNS resolving does not work for them (of
>     course, it is to blame for authoritative servers of a specific
>     domain).
>     But I have to solve it somehow.
>     Thanks.
>     Mira
>     Dne 18. 09. 20 v 15:34 Winfried Angele napsal(a):
>>     Hi Mira,
>>     Yes the Recursor does no retry on *this* auth. But it tries on
>>     the other nameservers from the NS RR set. IPv4 and IPv6. So if
>>     you have only one auth, Recursor tries two times, IPv4 and IPv6
>>     if available.
>>     Winfried
>>     Am 18. September 2020 14:47:49 MESZ schrieb Mira Krejci via
>>     Pdns-users <pdns-users at mailman.powerdns.com>:
>>         Hi,
>>         I have a problem that I can't force the pdns recursor to query the
>>         authoritative servers repeatedly if they do not answer. Recursor tries
>>         the query only once and then return an error (SERVFAIL) to the client.
>>         This is very problematic when the authoritative server is overloaded or
>>         there are some problems on the network. I didn't find any way in the
>>         configuration to change it.
>>         Server version: 4.2.2-1 (from EPEL repo on CentOS 8)
>>         Can anyone help?
>>         Thanks.
>>         Mira
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