[systemd-devel] Systems-resolved: Calling gethostbyaddr on non-local/non-private causes connection attempt

[Cristian Rodríguez]

On Fri, Feb 23, 2024 at 4:37 PM Anthony_Fuller at trendmicro.com
<Anthony_Fuller at trendmicro.com> wrote:
>
> I tried this on a fresh installation of Fedora Workstation 39. I installed wireshark and set the filter to `tcp.port == 5355` then ran the python script again with an ip of `123.123.123.123` and I see an outbound connection attempt to IP 123.123.123.123 on port 5355.

Sorry, I had LLMNR disabled..even MS says we should use MDNS instead.

Indeed
python3 -c 'import socket; socket.gethostbyaddr("123.123.123.123")'

results in an LLMR lookup.. apparently only if dns fails.

if this is not correct according to the spec, file a bug report.