PlusNet's DNS Servers are broken for some domains

[#1]

I tried reporting this via support, and they redirected me to the Broadband Fault Checker... I tried reporting via that, and it broke! ("There's been a problem"). Seeing as I'm not allowed to file just a simple ticket, filing here and hopefully a staff member will notice.

I'm trying to access some domains, and the servers are returning SERVFAIL. Here's the dig output:

$ dig @212.159.6.10 planet.mozilla.org

; <<>> DiG 9.10.6 <<>> @212.159.6.10 planet.mozilla.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 32997
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;planet.mozilla.org.        IN    A

;; Query time: 375 msec
;; SERVER: 212.159.6.10#53(212.159.6.10)
;; WHEN: Fri Apr 06 09:08:10 BST 2018
;; MSG SIZE  rcvd: 47

$ dig @212.159.6.9 wiki.mozilla.org

; <<>> DiG 9.10.6 <<>> @212.159.6.9 wiki.mozilla.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 50494
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;wiki.mozilla.org.        IN    A

;; Query time: 385 msec
;; SERVER: 212.159.6.9#53(212.159.6.9)
;; WHEN: Fri Apr 06 09:08:59 BST 2018
;; MSG SIZE  rcvd: 45

If I use a different server I get:

$ dig @1.1.1.1 planet.mozilla.org

; <<>> DiG 9.10.6 <<>> @1.1.1.1 planet.mozilla.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15928
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1536
;; QUESTION SECTION:
;planet.mozilla.org.        IN    A

;; ANSWER SECTION:
planet.mozilla.org.    55    IN    CNAME    www.haul.prod.core.us-west-2.appsvcs-generic.nubis.allizom.org.
www.haul.prod.core.us-west-2.appsvcs-generic.nubis.allizom.org.    125 IN CNAME haul-web-prod-1392505985.us-west-2.elb.amazonaws.com.
haul-web-prod-1392505985.us-west-2.elb.amazonaws.com. 55 IN A 35.162.26.49
haul-web-prod-1392505985.us-west-2.elb.amazonaws.com. 55 IN A 35.164.68.109

;; Query time: 16 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Fri Apr 06 08:55:12 BST 2018
;; MSG SIZE  rcvd: 218

Feels like something I had a few years ago when the DNS servers were being crazy. At least then I was able to file a simple ticket to get it through to the right people.

In the meantime, I guess I'm changing DNS servers.

[#2]

Not surprisingly I get the same problem with Plusnet caching DNS, but it's OK from elsewhere (Google). I've escalated this into the business.

[#3]

Is this an intermittent issue?

~ $ dig planet.mozilla.org @212.159.6.10

; <<>> DiG 9.9.5-9+deb8u13-Raspbian <<>> planet.mozilla.org @212.159.6.10
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37057
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 4, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;planet.mozilla.org.            IN      A

;; ANSWER SECTION:
planet.mozilla.org.     60      IN      CNAME   www.haul.prod.core.us-west-2.appsvcs-generic.nubis.allizom.org.
www.haul.prod.core.us-west-2.appsvcs-generic.nubis.allizom.org. 300 IN CNAME haul-web-prod-1392505985.us-west-2.elb.amazonaws.com.
haul-web-prod-1392505985.us-west-2.elb.amazonaws.com. 60 IN A 35.162.26.49
haul-web-prod-1392505985.us-west-2.elb.amazonaws.com. 60 IN A 35.164.68.109

;; AUTHORITY SECTION:
us-west-2.elb.amazonaws.com. 686 IN     NS      ns-1475.awsdns-56.org.
us-west-2.elb.amazonaws.com. 686 IN     NS      ns-1769.awsdns-29.co.uk.
us-west-2.elb.amazonaws.com. 686 IN     NS      ns-332.awsdns-41.com.
us-west-2.elb.amazonaws.com. 686 IN     NS      ns-560.awsdns-06.net.

;; Query time: 365 msec
;; SERVER: 212.159.6.10#53(212.159.6.10)
;; WHEN: Fri Apr 06 14:07:47 BST 2018
;; MSG SIZE  rcvd: 352   

[#4]

@bobpullen It was a permanent problem when the posts here (and my escalation) were made, but is working again now.

Previously the first query returned a CNAME correctly. The second query should also return a CNAME but SERVFAIL was returned. Now this works and is followed through to the A records.

But the Google DNS - I used 8.8.8.8 - resolved throughout.

[#5]

There's a new(ish) DNS server in town - 1.1.1.1

Described in https://1.1.1.1/

[#6]

@spraxyt, OK thanks. Shout if things go wobbly again.