DNS
Links
Check if the txt record has been processed
host -t txt _acme-challenge.example.com
Show SOA records
host -t soa domain.com
DNS on Debian Bookworm
Ubuntu differs from Debian!
apt install systemd-resolved
DNS on Ubuntu using netplan
Maybe the better approach?
DNS on Ubuntu using resolvconf
Don’t use resolvconf on Debian.
Systemd priorizes on-link DNS server over global DNS server over global fallback DNS servers in its default settings.
apt install resolvconf
Make sure that /etc/resolv.conf is a symlink to /run/resolvconf/resolv.conf
ln -s /run/resolvconf/resolv.conf /etc/resolv.conf
Check CAA record
dig CAA yourdomain.com +noall +answer
Verify DNSSEC
Check the DNSKEY record:
dig DNSKEY you.com +dnssec +noall +answer
And test an A record
dig A host1.you.com +dnssec +noall +answer
Or go to DNSViz or DNSSEC Analyzer.