Dos documentos do RHEL7 , conforme informado nos comentários do usuário @ val0x00ff:
In Red Hat Enterprise Linux 7, udev supports a number of different naming schemes. The default is to assign fixed names based on firmware, topology, and location information.
This has the advantage that the names are fully automatic, fully predictable, that they stay fixed even if hardware is added or removed (no re-enumeration takes place), and that broken hardware can be replaced seamlessly.
The disadvantage is that they are sometimes harder to read than the eth0 or wlan0 names traditionally used. For example: enp5s0.
(...)
By default, systemd will name interfaces using the following policy to apply the supported naming schemes:
- Scheme 1: Names incorporating Firmware or BIOS provided index numbers for on-board devices (example: eno1), are applied if that information from the firmware or BIOS is applicable and available, else falling back to scheme 2.
- Scheme 2: Names incorporating Firmware or BIOS provided PCI Express hotplug slot index numbers (example: ens1) are applied if that information from the firmware or BIOS is applicable and available, else falling back to scheme 3.
- Scheme 3: Names incorporating physical location of the connector of the hardware (example: enp2s0), are applied if applicable, else falling directly back to scheme 5 in all other cases.
- Scheme 4: Names incorporating interface's MAC address (example: enx78e7d1ea46da), is not used by default, but is available if the user chooses.
- Scheme 5: The traditional unpredictable kernel naming scheme, is used if all other methods fail (example: eth0).
(ênfase minha)