Can't resolve name - proxy 504 DNS lookup failed

I am new here so starting: Hello Everybody!
I am looking for a help with one website.
We are using proxy server which has setup as a DNS server.
When trying to access unfortunately from time to time we get 504 error DNS lookup failed while it works without proxy.
The weired thing is that when the issue occurs the nslookup (with works properly and the name can be resolved however using for example the name can’t be resolved (for but for other resolvers (for example it can.

Can you please point me what can be the problem behind this?

Thank you in advance.

Can you post a screenshot of that error? 504 shouldnt be a DNS error.

The domain appears to exist, seems to have general DNS resolution issues though.

Hi Sandro,

Here is the screenshot of the error.

When I try access it using curl (via proxy) I am getting Gateway Timeout

HTTP/1.1 504 Gateway Timeout
Connection: close
Content-Type: text/html
Cache-Control: no-cache
Content-Length: 1124


Thats an error on the site, not a Cloudflare error. They might have a reverse proxy which cant resolve the target host, but thats just speculation. is not resolving for me also, but it seems an issue of their nameservers or DNS configuration (they are returning no A record, but they do return MX record)

Are you using Cloudflare’s resolver or another one? Their nameservers do seem to return some values, but it seems their DNS servers are not agreeing on some things. So it seems to be a configuration issue on their side.

The problem seems to be intermittent, I will try to check it with some other resolver during the issue.
For me they do use two nameservers and The first one returns A record but the second does not . Could be the reason that during issue we are asking the server which does not return the A record?

For example there is also which works correctly and the A record is returned by both nameservers

It could and most likely is the reason. Simply put their DNS configuration is faulty.

Hi Guys,
Since their name servers return the “A” records it works as expected.

Thank for your help