Bug#1110883: release-notes: mDNS resolution in systemd-resolved disabled by default, breaking existing setups

On Tue, 12 Aug 2025 at 15:27, Colin Crawford <[email protected]> wrote:
>
> Hi Chris,
>
> Thanks for the quick reply. I'm not a developer, so I'm afraid I don't know what an MR is or how to submit a patch. However, I've taken the text of the relevant NEWS item from the systemd-resolved package as a starting point for the text below. Please let me know if this draft is useful:
>
> For trixie, mDNS support is now globally disabled by default in systemd-resolved.

can we explain what mDNS is - or link to somewhere that does. i have
tried and failed to understand what it's purpose is before, without
success.

> Users relying on mDNS who are not already using Avahi

this bit is a bit confusing as it starts talking about one package and
then mentions avahi which is a different package. I suggest:


In trixie, systemd-resolved no longer enables mDNS support by default
to prevent conflicts with the avahi. mDNS is [xxxx]

To continue using systemd-resolved's mDNS support you can run the
following as root:

       mkdir -p /etc/systemd/resolved.conf.d/
       touch /etc/systemd/resolved.conf.d/00-disable-mdns.conf

It is recommended to do this before upgrading to ensure your system
remains reachable.