Chapter 8. Consistent Network Device Naming
eth[0123…], but these names do not necessarily correspond to actual labels on the chassis. Modern server platforms with multiple network adapters can encounter non-deterministic and counter-intuitive naming of these interfaces. This affects both network adapters embedded on the motherboard (Lan-on-Motherboard, or LOM) and add-in (single and multiport) adapters.
ethXstyle names, where X is a unique number corresponding to a specific interface and may have different names of network interfaces during the boot process. For more details, see Section 8.10, “Troubleshooting Network Device Naming”.
8.1. Naming Schemes Hierarchy
systemdwill 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:
biosdevname=1as a kernel command-line parameter, except in the case of a Dell system, where biosdevname will be used by default as long as it is installed. If the user has added udev rules which change the name of the kernel devices, those rules will take precedence.