Setup DNSSEC DNSOVERTLS on systemd-resolved
sudo vim /etc/systemd/resolved.conf
[Resolve] # Some examples of DNS servers which may be used for DNS= and FallbackDNS=: # Cloudflare: 1.1.1.1#cloudflare-dns.com 1.0.0.1#cloudflare-dns.com 2606:4700:4700::1111#cloudflare-dns.com 2606:4700:4700::1001#cloudflare-dns.com # Google: 8.8.8.8#dns.google 8.8.4.4#dns.google 2001:4860:4860::8888#dns.google 2001:4860:4860::8844#dns.google # Quad9: 9.9.9.9#dns.quad9.net 149.112.112.112#dns.quad9.net 2620:fe::fe#dns.quad9.net 2620:fe::9#dns.quad9.net DNS= 1.1.1.1#cloudflare-dns.com 1.0.0.1#cloudflare-dns.com 2606:4700:4700::1111#cloudflare-dns.com 2606:4700:4700::1001#cloudflare-dns.com FallbackDNS= 8.8.8.8#dns.google 8.8.4.4#dns.google 2001:4860:4860::8888#dns.google 2001:4860:4860::8844#dns.google #Domains= DNSSEC=yes DNSOverTLS=yes #MulticastDNS=no #LLMNR=resolve Cache=yes #CacheFromLocalhost=no #DNSStubListener=yes #DNSStubListenerExtra= ReadEtcHosts=yes #ResolveUnicastSingleLabel=no
sudo systemctl restart NetworkManager