As indicated by the error message, netplan does not support specifying a non-default port for DNS servers; it will only use port 53. I see that systemd-resolved does support non-default ports, so this is a valid feature request for netplan, best reported at https://bugs.launchpad.net/netplan.
I have personally never heard before of providers offering DNSSEC on an alternate port. You might check with your provider if they have a DNSSEC endpoint running on port 53 but a different IP address.
As @slangasek pointed out configuring port 853 for an dns entry with netplan is not supported.
/etc/systemd/resolved.conf is the current way in ubuntu.
# See resolved.conf(5) for details
[Resolve]
DNS=1.1.1.1
FallbackDNS=
#Domains=
LLMNR=no
MulticastDNS=no
DNSSEC=yes
DNSOverTLS=yes
#Cache=yes
DNSStubListener=no
As indicated by the error message, netplan does not support specifying a non-default port for DNS servers; it will only use port 53. I see that systemd-resolved does support non-default ports, so this is a valid feature request for netplan, best reported at https://bugs.launchpad.net/netplan.
I have personally never heard before of providers offering DNSSEC on an alternate port. You might check with your provider if they have a DNSSEC endpoint running on port 53 but a different IP address.
As @slangasek pointed out configuring port 853 for an dns entry with netplan is not supported.
/etc/systemd/resolved.confis the current way in ubuntu.