On 26-03-2025 20:32, Roy Bixler via Dng wrote:
> /etc/udev/rules.d/75-cloud-ifupdown.rules:
>
> # Handle allow-hotplug interfaces
> SUBSYSTEM=="net", ACTION=="add", ENV{INTERFACE}=="eth*|en*", RUN+="/etc/network/cloud-ifupdown-helper"

Afaik an ethernet device name always start with an e so the udev rule
could be even simpler:

SUBSYSTEM=="net", ACTION=="add", ENV{INTERFACE}=="e*",
RUN+="/etc/network/cloud-ifupdown-helper"