> Can you attach the output of > systemctl status systemd-networkd.service > journalctl -ulb systemd-networkd.service > > for both containers. >
Older 11.2 container: root@11-2:~# systemctl status systemd-networkd.service Warning: The unit file, source configuration file or drop-ins of systemd-networkd.service changed on disk. Run 'systemctl daemon-reload' to reload units. ● systemd-networkd.service Loaded: masked (Reason: Unit systemd-networkd.service is masked.) Drop-In: /run/systemd/system/service.d └─zzz-lxc-service.conf Active: inactive (dead) root@11-2:~# journalctl -ulb systemd-networkd.service Failed to add match 'systemd-networkd.service': Invalid argument Newly created 11.3 container (11test2): root@11test2:~# systemctl status systemd-networkd.service ● systemd-networkd.service - Network Service Loaded: loaded (/lib/systemd/system/systemd-networkd.service; disabled; vendor preset: enabled) Drop-In: /run/systemd/system/service.d └─zzz-lxc-service.conf Active: active (running) since Tue 2022-04-12 13:56:00 UTC; 34s ago TriggeredBy: ● systemd-networkd.socket Docs: man:systemd-networkd.service(8) Main PID: 85 (systemd-network) Status: "Processing requests..." Tasks: 1 (limit: 619000) Memory: 4.0M CPU: 38ms CGroup: /system.slice/systemd-networkd.service └─85 /lib/systemd/systemd-networkd Apr 12 13:55:59 11test2 systemd[1]: Starting Network Service... Apr 12 13:56:00 11test2 systemd-networkd[85]: eth0: Gained IPv6LL Apr 12 13:56:00 11test2 systemd-networkd[85]: Enumeration completed Apr 12 13:56:00 11test2 systemd[1]: Started Network Service. root@11test2:~# journalctl -ulb systemd-networkd.service Failed to add match 'systemd-networkd.service': Invalid argument There's the following diff in the zzz-lxc-service.conf: root@11test2:~# diff /run/systemd/system/service.d/zzz-lxc-service.conf /tmp/zzz-lxc-service-11.2.conf 2d1 < ProcSubset=all So the reason for the previously working case seems to be because the systemd-networkd service was actually masked before. Where and why the mask did come from? No idea... > > If systemd-networkd wasn't running in your old, 11.2 based container, it > couldn't interfere with your custom network setup. > > This is btw I recommended to disable systemd-networkd as the correct > solution for your issue. > Yes, that's fine for me. I'll adjust our template for that case. In Ubuntu we need to do the same with Netplan.