[MAYBE SOLVED] resolving hosts problem after pacman -Syu

[dobunzli]

Hello,
I have Linux archpi 4.19.69-2-ARCH #1 SMP PREEMPT Wed Sep 4 00:55:25 UTC 2019 armv7l GNU/Linux running on a raspberry pi3b+.

Everything was ok before I made a sudo pacman -syu and reboot. Since then I am not able to resolve hosts anymore.

Examples
sudo pacman -syu throws
$this->bbcode_second_pass_code('', '...
error: failed retrieving file 'core.db' from mirror.archlinuxarm.org : Could not resolve host: mirror.archlinuxarm.org
...
')

If I try to ping http://www.google.com it throws
$this->bbcode_second_pass_code('', '
ping: www.google.com: Name or service not known')

Internet access is OK as I have services that are accessible from the outside via a dyndns on this machine.

Can you please help me and suggest further steps to debug ?

Thanks in advance.

[dobunzli]

Hello again,

I think I narrowed it down... problem is maybe because of a new configuration for systemd-resolved.

In /etc/systemd/resolved.conf I changed: #DNSSEC=allow-downgrade to DNSSEC=no.

Then restart with sudo systemctl restart systemd-resolved

And now ping http://www.google.com or sudo pacman -Syu is working again...

You can also check that configuration is OK with:
$this->bbcode_second_pass_quote('', '
')$ resolvectl dnssec
Global: no
Link 6 (veth46f341b): no
Link 4 (docker0): no
Link 3 (wlan0): no
Link 2 (eth0): no

[graysky]

Same problem and solution here.