problem resolving cdn.darkserv.net

[Daisuke HIGASHI]

Seems 0x20 problem with darkserv.net -- "use-caps-for-id: no" ?

=====================
% dig @ns2.darkserv.net cDn.darkserv.net
; <<>> DiG 9.10.6 <<>> @ns2.darkserv.net cDn.darkserv.net
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 17819
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232

;; QUESTION SECTION:
;cDn.darkserv.net. IN A
=====================


A. Schulze via Unbound-users <unbound-users at lists.nlnetlabs.nl>:
>
> Hello,
>
> unbound-1.14.0 (as well as 1.13.2) can't revolve cdn.darkserv.net.
> I seen lots of the folloging messages (verbose: 2)
>
> Dec 13 12:44:53 unbound[22:0] info: query response was THROWAWAY
> Dec 13 12:44:53 unbound[22:0] info: response for cdn.darkserv.net. A IN
> Dec 13 12:44:53 unbound[22:0] info: reply from <darkserv.net.> 144.217.187.53#53
> Dec 13 12:44:53 unbound[22:0] info: query response was THROWAWAY
> Dec 13 12:44:54 unbound[22:0] info: response for cdn.darkserv.net. A IN
> Dec 13 12:44:54 unbound[22:0] info: reply from <darkserv.net.> 2001:41d0:2:aa69::53#53
>
> I think, the nameservers itself have some kind of "edns-problem" but i don't understand it in detail.
>
> zonemaster.net and EDNS Compliance Tester report different results for the same servers
> or I simply don't see the difference...
>
> darkserv.net:
>
> - https://zonemaster.net/result/09db767380529a57
> - https://ednscomp.isc.org/ednscomp/ee95621712
>
> the same 4 servers are also authoritative for cdn.darkserv.net
> and now there are no EDNS errors !?
>
> - https://zonemaster.net/result/3f585012c88f40b9
> - https://ednscomp.isc.org/ednscomp/b3bfd09b8b
>
> anyway: this is my unexpected problem:
>
> $ kdig @127.0.0.1 cdn.darkserv.net.
> ;; ->>HEADER<<- opcode: QUERY; status: SERVFAIL; id: 39664
> ;; Flags: qr rd ra; QUERY: 1; ANSWER: 0; AUTHORITY: 0; ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;; cdn.darkserv.net.            IN      A
>
> ;; Received 34 B
> ;; Time 2021-12-13 12:44:51 CET
> ;; From 127.0.0.1 at 53(UDP) in 2690.9 ms
>
> any ideas?
>
> Andreas