@lanodan @fleaz The MAC address might be actually the most predictable of them (unless you set the interface names yourself), at least for the x86-* world: onboard device number ('o') depends on the capabilities of firmware, the positions ('p') can renumber when adding/removing devices (happened to me when I removed WiFi M.2 module from a laptop).

I have probably never seen a computer (apart from a VM) to use the PCIe port numbers ('s'), so I can't say whether they can be reliable.

(And for the embedded devices: when the OS sets the MAC address, it is supposedly controlled by the admin, so safe to match against, isn't it? It just means that on any change of MAC you might need to change multiple configs, which sucks, but IMHO much less than having the device be offline because the "predictable" name changed…)