> but an unsatisfied client will still query again. Yes, but the Recursor will answer this client retries with SERVFAIL for <packetcache-servfail-ttl> seconds without asking the Auth again. And it will not ask an unresponsive Auth for <server-down-throttle-time> seconds.
Winfried Am 21. September 2020 15:14:49 MESZ schrieb Mira Krejci via Pdns-users <pdns-users@mailman.powerdns.com>: >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. > >Mira > >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 ><kre...@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@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 >>> >------------------------------------------------------------------------ >>> Pdns-users mailing list >>> Pdns-users@mailman.powerdns.com >>> https://mailman.powerdns.com/mailman/listinfo/pdns-users >>> >>
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