Intermittent SERVFAIL looking up CAA

I had some issues trying to get the certificates with the WWW domain not being recognized, but eventulally got the command to issue them to work. However now when I try to dry run the renewal I get error either with the WWW domain or both.

My domain is: advocatesays.click and www.advocatesays.click

I ran this command: certbot renew --dry-run

It produced this output:

Saving debug log to /var/log/letsencrypt/letsencrypt.log

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Processing /etc/letsencrypt/renewal/advocatesays.click.conf
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Simulating renewal of an existing certificate for advocatesays.click and www.advocatesays.click

Certbot failed to authenticate some domains (authenticator: nginx). The Certificate Authority reported these problems:
  Domain: www.advocatesays.click
  Type:   dns
  Detail: During secondary validation: DNS problem: SERVFAIL looking up CAA for advocatesays.click - the domain's nameservers may be malfunctioning

  Domain: advocatesays.click
  Type:   dns
  Detail: During secondary validation: DNS problem: SERVFAIL looking up CAA for advocatesays.click - the domain's nameservers may be malfunctioning

Hint: The Certificate Authority failed to verify the temporary nginx configuration changes made by Certbot. Ensure the listed domains point to this nginx server and that it is accessible from the internet.

Failed to renew certificate advocatesays.click with error: Some challenges have failed.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
All simulated renewals failed. The following certificates could not be renewed:
  /etc/letsencrypt/live/advocatesays.click/fullchain.pem (failure)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 renew failure(s), 0 parse failure(s)
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.

My web server is (include version):

nginx version: nginx/1.18.0 (Ubuntu)

The operating system my web server runs on is (include version):

Ubuntu 20.04.3 LTS

My hosting provider, if applicable, is: DigitalOcean

I can login to a root shell on my machine (yes or no, or I don't know): yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot):

It looks like your authoritative DNS is not playing nice. You should set a CAA record, and it's either a transient issue, or you should ask njalla support.

peppe@monolite:~$ for ns in $(dig +short ns advocatesays.click); do dig @$ns caa advocatesays.click; done

; <<>> DiG 9.16.1-Ubuntu <<>> @2-can.njalla.in. caa advocatesays.click
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50049
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: e4f2a9fa9f50d6541dd1dded61f905e307aa38df6a596942 (good)
;; QUESTION SECTION:
;advocatesays.click.            IN      CAA

;; AUTHORITY SECTION:
advocatesays.click.     10800   IN      SOA     1-you.njalla.no. you.can-get-no.info. 2201311158 21600 7200 1814400 86400

;; Query time: 38 msec
;; SERVER: 185.193.124.34#53(185.193.124.34)
;; WHEN: Tue Feb 01 11:05:22 CET 2022
;; MSG SIZE  rcvd: 145


; <<>> DiG 9.16.1-Ubuntu <<>> @3-get.njalla.fo. caa advocatesays.click
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51701
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 35fcefc095622b578f7d6f6761f905e3b88f8092c417df90 (good)
;; QUESTION SECTION:
;advocatesays.click.            IN      CAA

;; AUTHORITY SECTION:
advocatesays.click.     10800   IN      SOA     1-you.njalla.no. you.can-get-no.info. 2201311158 21600 7200 1814400 86400

;; Query time: 78 msec
;; SERVER: 95.215.19.5#53(95.215.19.5)
;; WHEN: Tue Feb 01 11:05:22 CET 2022
;; MSG SIZE  rcvd: 145


; <<>> DiG 9.16.1-Ubuntu <<>> @1-you.njalla.no. caa advocatesays.click
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55239
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 4f6c15b613a8c1e27f028ea361f905e3c462bc3ad9d0a014 (good)
;; QUESTION SECTION:
;advocatesays.click.            IN      CAA

;; AUTHORITY SECTION:
advocatesays.click.     10800   IN      SOA     1-you.njalla.no. you.can-get-no.info. 2201311158 21600 7200 1814400 86400

;; Query time: 38 msec
;; SERVER: 185.193.124.2#53(185.193.124.2)
;; WHEN: Tue Feb 01 11:05:22 CET 2022
;; MSG SIZE  rcvd: 145

peppe@monolite:~$

I don't have much experience in this area. Do I just set it up as Type: CAA, Name: @, Content: letsencrypt.org?

No.

Read here for more info and how to generate your record:

2 Likes

Ok, following the guide you linked the first step that I must do when encountering SERVFAIL is run my domain names through https://dnsviz.net/. I seem to be getting warnings about DNSSEC specification prohibiting signing with DS records that use digest algorithm 1 (SHA-1) and that DNSSEC specification recommends not signing with DNSSEC algorithm 5 (RSASHA1). Not really sure how to follow those warnings.

Based on some examples in the article do I need to put my two domain names as Name for CAA records?

I don't know if that's an actual issue, and you might not have any control about it.

just put the apex domain, www will inherit it

1 Like

Ok, I tried putting in Type: CAA, Name: advocatesays.click and Content: "0 issue letsencrypt.org" (same as example value in that field in the UI) and I got a warning back "failed to add record". Is there some logical error with the record I am trying to add or should I contact the njalla support?

You should probably read here first, and then contact njalla.

1 Like

If you're not able to add the CAA record due to some error in the DNS zone editor then yes, you should consult with your DNS service provider on how to actually add the CAA record. Nothing we can help you with in that regard.

As for your intermittend SERVFAILs: currently Unboundtest does not return an error: https://unboundtest.com/m/CAA/advocatesays.click/P3TKAZVG

And also the fact the SERVFAILs come from secondary servers and not the primary one suggests there might be something going on with your DNS which is pretty hard to debug. I'm not sure if adding the CAA record will actually help, but doesn't hurt to try.

All those warnings @ DNSViz do suggest to me that the .click top-level domain isn't very well set up, but I don't see a clear reason for SERVFAILs at that test. But depending on from where in the world DNSViz initiates the test, this might be a false-negative. Perhaps other servers of the .click TLD or the lower name servers (uniregistry.net?) have something bad going on somewhere else in the world.

2 Likes

This is the response I got from the support:

The domain resolves, SSL you do on the server side and letsencrypt.org have all the documentation.

What did you ask specifically? Usually to get a correct, sensible answer, the question needs to be correct too.

2 Likes

If you're not able to add the CAA record due to some error in the DNS zone editor then yes, you should consult with your DNS service provider on how to actually add the CAA record.

Well, I was asking to confirm if it was that or if what I was inputting doesn't make sense.

And also the fact the SERVFAILs come from secondary servers and not the primary one suggests there might be something going on with your DNS which is pretty hard to debug.

You mean the DNS of my host (DigitalOcean)?

All those warnings @ DNSViz do suggest to me that the .click top-level domain isn't very well set up,

This is my current setup: I have added two DNS records:

  1. Type: A, Name: advocatesays.click, IP: (ip address)
  2. Type: A, Name: www.advocatesays.click, IP: (same ip address)

Here is the content of my ticket there:

Intermittent SERVFAIL looking up CAA with Let's Encrypt certbot

I keep getting SERVFAIL when trying to verify the domain with Let's Encrypt. More info here:

Intermittent SERVFAIL looking up CAA

Any suggestions on what to add?

The part about secondary servers is from the Let's Encrypt side: LE uses 4 different vantage points around the world, 1 being the "primary" and 3 others being "secondary". If the primary succeeds, but 2 out of 3 of the secondary vantage points fail, the validation in total will fail and add "secondary" in the error message to specify this specifically.

For the CAA record? Well, they didn't answer you apparently..

Ah, so you didn't ask your DNS support about the error you got when you tried to add the CAA record.

2 Likes

The part about secondary servers is from the Let's Encrypt side: LE uses 4 different vantage points around the world, 1 being the "primary" and 3 others being "secondary". If the primary succeeds, but 2 out of 3 of the secondary vantage points fail, the validation in total will fail and add "secondary" in the error message to specify this specifically.

So what exactly is considered "my" DNS servers which I need to look into about something going on with them? Since I do not personally maintain and public DNS servers.

For the CAA record? Well, they didn't answer you apparently..

I mean, I posted here earlier what I tried inputting as CAA record to check if it is logically sound.

Ah, so you didn't ask your DNS support about the error you got when you tried to add the CAA record.

I'll add that to the ticket.

So, the support at njalla added the aforementioned CAA entry for me. Unfortunately, I still seem to be facing the same issue:

# certbot renew --dry-run
Saving debug log to /var/log/letsencrypt/letsencrypt.log

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Processing /etc/letsencrypt/renewal/advocatesays.click.conf
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Simulating renewal of an existing certificate for advocatesays.click and www.advocatesays.click

Certbot failed to authenticate some domains (authenticator: nginx). The Certificate Authority reported these problems:
  Domain: advocatesays.click
  Type:   dns
  Detail: DNS problem: SERVFAIL looking up CAA for advocatesays.click - the domain's nameservers may be malfunctioning

Hint: The Certificate Authority failed to verify the temporary nginx configuration changes made by Certbot. Ensure the listed domains point to this nginx server and that it is accessible from the internet.

Failed to renew certificate advocatesays.click with error: Some challenges have failed.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
All simulated renewals failed. The following certificates could not be renewed:
  /etc/letsencrypt/live/advocatesays.click/fullchain.pem (failure)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 renew failure(s), 0 parse failure(s)
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.

What else can I try?

1 Like

I don't know. Unboundtest can indeed see your CAA resource record and does not give a SERVFAIL: https://unboundtest.com/m/CAA/advocatesays.click/DWTD6HH5

Let's Debug also doesn't show any issues: Let's Debug

And when I try to get a certificate for your site (which will fail ultimately of course), it does not complain about CAA records, just the failed validation attempt..?

2 Likes

I just tried it two times in a row and one time it failed and one it didn't.

It's probably a rather hard to debug issue with something at the DNS. Doesn't necessarily have to be the DNS hosting provider, but might as well be the DNS infrastructure of the .click top level domain. Hard if not impossible to tell I think, although all those warnings at DNSViz doesn't make me feel hopeful about the .click TLD.. I hope you didn't pay too much money for your domain!

1 Like

It was 15 euros for a year. So, is there a way to escalate it to TLD owenrs orsmth?