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

[Winfried Angele]

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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