Public DNS occasionally fails to resolve specific site

CloudFlare’s public DNS resolver occasionally fails to resolve only wolframalpha.com while Google’s public DNS resolver can resolve it just fine. This is tested with both IPv6, IPv4, and with DNS-Over-HTTPS on and off. I have not encountered another domain name that 1.1.1.1 fails to resolve.

nslookup result:
C:\Users\Testificate>nslookup wolframalpha.com 8.8.8.8
Server: dns.google
Address: 8.8.8.8

Non-authoritative answer:
Name:    wolframalpha.com
Address:  140.177.204.192


C:\Users\Testificate>nslookup wolframalpha.com 1.1.1.1
Server:  one.one.one.one
Address:  1.1.1.1

*** one.one.one.one can't find wolframalpha.com: Server failed

tracert 1.1.1.1 result:
Tracing route to one.one.one.one [1.1.1.1]
over a maximum of 30 hops:

  1     5 ms     5 ms     5 ms  192.168.1.254
  2     8 ms     6 ms     7 ms  d64-180-196-1.bchsia.telus.net [64.180.196.1]
  3     8 ms     6 ms     7 ms  154.11.10.159
  4     7 ms    44 ms     8 ms  as13335.vanix.ca [206.41.104.52]
  5     9 ms     9 ms     7 ms  one.one.one.one [1.1.1.1]

Trace complete.

I just noticed the same when I try to access wolframalpha, occasionally it works but mostly not today. If I connect via vpn or such that uses a different dns it works fine.

Hi, seems like there’s an issue with wolframalpha.com DNS infrastructure, as it sometimes returns an empty answer:

;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 37929
;; Flags: qr ra  QUERY: 1; ANSWER: 0; AUTHORITY: 2; ADDITIONAL: 3

;; EDNS PSEUDOSECTION:
;; Version: 0; flags: ; UDP size: 4096 B; ext-rcode: Unused

;; QUESTION SECTION
wolframalpha.com.		A

;; AUTHORITY SECTION
wolframalpha.com.   	5333	NS	wri-dns0.wolfram.com.
wolframalpha.com.   	5333	NS	wri-dns1.wolfram.com.

;; ADDITIONAL SECTION
wri-dns1.wolfram.com.	6602	A	140.177.203.1
wri-dns0.wolfram.com.	5475	A	140.177.205.10

It is more noticeable since the responses are cached for the whole PoP. I’ll try to contact wolframalpha to see if this can be fixed.

This should be now resolved (also confirmed from our side).