Hi,
Please show your configuration.
I do not think your analysis is to the point.
If I repeat a scenario, I see a correct retrieval of the A record.
So we have to find out what is different in your case.
-Otto
On Thu, Jan 26, 2023 at 01:30:54PM +0100, Arien Vijn via Pdns-users wrote:
> Greetings,
>
> We recently upgraded pdns_recursor from version 4.4.5 to 4.8.0. It seems that
> we run in into the following issue ever since.
>
> 1/ Client queries for an A-record for xdsl-serviceweb.kpn.com.
> 2/ Recursor queries the domain tree and receives the CNAME-record that points
> to: xdsl-c-serviceweb.gslb.kpn.com. from the authoritative DNS server.
> 3/ Recursor queries and receives the subsequent an A-record from the
> authoritative DNS server for that A-record.
> 4/ Recursor answers the client mentioned in 1/.
>
> So far so good, until the A-record of xdsl-c-serviceweb.gslb.kpn.com. expires
> out of the 'main record cache' but not from the 'main packet cache'. The
> CNAME remains in both caches. Please note this excerpt from: rec_control
> dump-cache below:
>
> ; main record cache dump follows
> ;
> xdsl-serviceweb.kpn.com. 300 -224 IN CNAME xdsl-c-serviceweb.gslb.kpn.com.
> ; (Secure) auth=1 zone=kpn.com from=194.151.228.10 nm= rtag= ss=0
> ; negcache dump follows
>
> [...]
>
> ; main packet cache dump from thread follows
> ;
> xdsl-c-serviceweb.gslb.kpn.com. -1803 A ; tag 0 udp
>
> [...]
>
> ; main packet cache dump from thread follows
> ;
> xdsl-serviceweb.kpn.com. -470 A ; tag 0 udp
> xdsl-serviceweb.kpn.com. 111 A ; tag 0 udp
> xdsl-serviceweb.kpn.com. 111 AAAA ; tag 0 udp
>
>
> From that point on, pdns_recursor replies on queries for the A-record with
> the SOA-record of the domain of the said A-record:
>
> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>>
> xdsl-c-serviceweb.gslb.kpn.com. @localhost
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36347
> ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 512
> ;; QUESTION SECTION:
> ;xdsl-c-serviceweb.gslb.kpn.com. IN A
>
> ;; AUTHORITY SECTION:
> gslb.kpn.com. 79407 IN SOA ns2gslb.kpn.com.
> netmaster.gslb.kpn.com. 2023011702 10800 3600 604800 86400
>
> ;; Query time: 0 msec
> ;; SERVER: ::1#53(::1)
> ;; WHEN: Thu Jan 26 12:10:13 CET 2023
> ;; MSG SIZE rcvd: 113
>
>
> This situation causes actual people to complain and is being resolved by
> removing the domain tree for the subdomain gslb.kpn.com. out of the caches.
> From then on the story starts again.
>
> That the A-record xdsl-c-serviceweb.gslb.kpn.com. remains in the packet cache
> seems not good to me, but I don't know enough about DNS and pdns_recursor be
> sure. What could trigger this behaviour or is it perhaps a configuration
> issue because we made such a large jump in versions when we upgraded? Last
> but not least we see the same behaviour with at least one other hostname
>
> -- Ari??n
>
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