[systemd-devel] systemd-resolved : How to change permanently to 127.0.0.54

[Laura Smith]

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On Monday, 23 December 2024 at 12:23, Adam Nielsen <a.nielsen at shikadi.net> wrote:

> But what's the underlying issue? Maybe there's a different fix? 

Its been a while so I can't remember the exact details, but I know its to do with Postfix.

Postfix creates a copy (not symlink) of /etc/resolv.conf in its /var/spool/postfix jail.

If the jail file contains 127.0.0.53 email is broken.  If changed to 127.0.0.54 email works.

As I said, its been a long time, but IIRC the underlying reason is something to do with DNNSEC validation and systemd-resolved breaks it with the 127.0.0.53 proxy.