Hi there. It seems that there is some ongoing issue using Cloudflare DNS (18.104.22.168) to resolve DuckDNS subdomains.
I’ve tested 6 different duckDNS sub-domains and each and every one of them are unable to get resolved using either 22.214.171.124 or 126.96.36.199 (did not try IPv6 as I do not have any DuckDNS AAAA records as of now)
Testing out the same domains using other public DNS services (like Google’s 188.8.131.52, IBM’s 184.108.40.206 or Level 3 220.127.116.11) all end up resolving the domain fine.
Example: dig @18.104.22.168 .duckdns.org works while dig @22.214.171.124 .duckdns.org fails.
Same goes for good old nslookup
126.96.36.199 = server can’t find .duckdns.org: SERVFAIL
188.8.131.52 = server can’t find .duckdns.org: SERVFAIL
I’ve seen one other recent thread on this issue, but aside suggesting changing your DNS provider, nothing else has been discussed. Now, what if the person on the other end cannot change their DNS settings, and want to use a duckDNS address (or a CNAME that resolve to a duckDNS entry…) It’s likely to fail.
(NOTE: I’ve replaced my real sub-domains with …)