DNS problem: query timed out looking up A


I’m trying to renew the certificate that handles two of my domains: cagd.co.uk and api.cagd.co.uk. When I tried two days ago I got “DNS problem: SERVFAIL looking up A for cagd.co.uk” errors. This morning I am getting “DNS problem: query timed out looking up A for cagd.co.uk

After some research, I discovered that there appear to be errors in the DNSSEC Authentication Chain at my DNS provider’s end:

cagd.co.uk zone: The server(s) were not responsive to queries over TCP. (,,


When I contacted them about this, they have said that when I installed the certificates from LetsEncrypt I “have changed the DNS record into secure ones provided by third party.” Is this true? I’ve been able to renew this certificate with no problem up until now – I’m wondering if something has changed in the past three months?

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:
cagd.co.uk, api.cagd.co.uk

I ran this command:
certbot certonly -d cagd.co.uk -d api.cagd.co.uk --manual

It produced this output:
Failed authorization procedure. api.cagd.co.uk (http-01): urn:acme:error:dns :: DNS problem: query timed out looking up A for api.cagd.co.uk, cagd.co.uk (http-01): urn:acme:error:dns :: DNS problem: query timed out looking up A for cagd.co.uk

My web server is (include version):

The operating system my web server runs on is (include version):
Ubuntu 14.04.5 LTS

My hosting provider, if applicable, is:

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

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


There’s an ongoing, unexplained issue with Let’s Encryot’s resolvers and your DNS provider (meganameservers.eu). See this thread:

There isn’t a known solution yet, other than changing DNS providers (or CAs). :slightly_frowning_face:

The only people who can answer that question are you and them.

Edit: Has it started to work if you try again now?


Yes, it’s just started to work again! :grinning: The DNSSEC errors are still there on my domains, but that doesn’t seem to be a problem now.

I think I will consider a different DNS provider mind you, but thank you for your help!


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