Public bug reported: For several reasons, we are not able to use netplan nor systemd-networkd due to legacy applications that expect ifupdown's pre-up and post-up script mechanism. The documentation around 18.04's (premature, I feel) wholesale adoption of netplan claims that one can revert to old behaviour by merely installing ifupdown (amongst assertions that netplan will never offer a mechanism for configuring pre-up and post-up actions even for network managers that support them).
However when ifupdown is installed, systemd-networkd still tries to manage interfaces. If you 'systemctl disable systemd-networkd', upon next reboot it is automatically re-enabled. We tried disabling any systemd units even remotely related to networking and yet systemd- networkd still runs. If it hasn't been configured, it tries to DHCP. On networks that don't provide DHCP this results in a stupendously long stall during boot. Currently it appears to be impossible to tell systemd-networkd not to run in a clean manner that won't get reverted on package upgrades. I sincerely hope this is is a bug/oversight and not intentional. We need to be able to disable systemd-networkd properly. Thanks ** Affects: ubuntu Importance: Undecided Status: New ** Summary changed: - forced use of systemd-networkd interferes with ifupdown + forced use of systemd-networkd interferes with ifupdown in 18.04 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1771236 Title: forced use of systemd-networkd interferes with ifupdown in 18.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1771236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs