I believe this is because in systemd v250 (which is in between 22.04's systemd v249, and 24.04's systemd v255), a network interface naming scheme was added for Xen netfront interfaces[1].
So, basically, udev is using a different name for the interface now. One way to work around this in the future would be to set your own interface name using the netplan config. By default, udev's policy is to keep interface names that were set by the admin. [1] https://www.freedesktop.org/software/systemd/man/latest/systemd.net- naming-scheme.html#v250 ** Changed in: systemd (Ubuntu) Status: New => Confirmed ** Changed in: systemd (Ubuntu) Importance: Undecided => Low -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2092945 Title: upgrade from 22 to 24 broke static ip To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2092945/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
