Question resolv.conf problems with Ubuntu 22.04 LTS

[D3nnis3n]

resolvectl dns ens6 127.0.0.1

worked.

Unfortunately, after a reboot, this is also overwritten and DNS is back to what 127.0.0.53 finds.
Anyone knows how one can permanently fix the DNS to 127.0.0.1 to allow spam blacklists to work reliably on Ubuntu 24.04?

 

[learning_curve]

Anyone knows how one can permanently fix the DNS to 127.0.0.1 to allow spam blacklists to work reliably on Ubuntu 24.04?

Quick questions (first of all):

a) Are you using Plesk E-Mail Security? (Plesk Extension Free and/or Paid)
b) Are your using netplan on your Ubuntu 24.04 LTS or, did your retain ifupdown form an older Ubuntu release during any Dist-Upgrades?
c) Further to THIS previous post in this thread, are you using systemd-resolve or resolvectl?
d) Can you post the result of: :~# systemd-resolve --status and :~# resolvectl status plus :~# ss -plnt | grep ':53' too, just for clarity?
e) Finally, can you explain in detail, what the actual issue is (for you / your curent config) regarding utilising the results provided by 127.0.0.53 and exactly which file (name / location) contains this command? (see next line). Is it just the functionality of Spam Blacklists as you've posted above? Or is there more?
e.g. ignoring any previous symlinks, is it here: /run/systemd/resolve/resolv.conf ? or here: /run/systemd/resolve/stub-resolv.conf ? and/or other locations too?

IF the overall (Ubuntu) config is correct, then THIS page (which is 24.04 LTS) explains the (intentional) use of a local DNS stub listener with the IP address 127.0.0.53, initially within the 'Description' section and then further on, in detail.

FWIW On Ubuntu 24.04 LTS (see forum sig) Plesk c/w Danami Jugernaut (so no Plesk Firewall and/or Fail2Ban), we have no issues at all, when using:
NO Plesk E-Mail Security / netplan / resolvectl & the symlink: resolv.conf -> ../run/systemd/resolve/stub-resolv.conf which, utilises the IP address 127.0.0.53