NetworkManager / systemd do not honor service dependencies on network-online.target

Hi!

I am using the as of this date latest armbian image Armbian 22.11 Jammy, Kernel 5.15.y, Size: 495Mb, CLI, Release date: Nov 30, 2022 for my board: https://www.armbian.com/rock64/

I am not sure if this is specifically an issue with the CLI image, or if both images are affected. I am not using a GUI. I configured a static IP address via netplan (generated and applied the config) and installed a dhcp server. The dhcp server sometimes kept failing to start on reboot. Checking the logs showed that even though the isc-dhcp-server depends on the network being configured before it tries to start, that actually systemd sometimes starts isc-dhcp-server before it configures the network interfaces. I believe this is a bug in the OS!

The only thing that helped was to completely remove/mask the default NetworkManager and switching to systemd-networkd and systemd-resolved instead.

I don't have time to report this in multiple bugtrackers, I am just documenting this issue here in the forum, and hopefully it will help somebody that has the same issue or who wants to fix this.

Also crossposted the issue to the isc dhcp-user mailinglist:  https://lists.isc.org/pipermail/dhcp-users/2023-February/022826.html

But I don't think it's a problem with their service. I think it's an issue with either systemd or NetworkManager or netplan with the default NetworkManager renderer.

If you want to reproduce the issue my netplan config looked like this:

cat /etc/netplan/armbian.yaml
network:
  version: 2
  renderer: NetworkManager
  ethernets:
    eth0:
      dhcp4: no
      addresses: [192.168.129.22/24]
      routes:
      - to: default
        via: 192.168.129.1
      nameservers:
        addresses: [1.1.1.1,8.8.8.8]

And after ripping out NetworkManger as I workaround I now I changed the renderer to networkd.

I think it would be better if the OS would also work as expected with the NetworkManager that it ships with enabled by default.

Or make networkd the new default.

Cheers!

Edited February 7, 20233 yr by Kwinz