# 20200624 coreos-status email about NIC naming

raw details:
- https://github.com/coreos/fedora-coreos-tracker/issues/484
- our names follow the old non-persistent eth* scheme
- this was done by mistake
- we need to use a persistent scheme (breaking change)
- when we make the change: newly installed systems will default to persistent NIC naming
- existing systems won't change (i.e. upgrades)
- use a barrier release that will add net.ifnames=0 to kargs
- next release after barrier release will default to persistent NIC naming, but upgraded systems will have net.ifnames=0 set so behavior won't change
- timeline:
- https://github.com/coreos/fedora-coreos-tracker/issues/484#issuecomment-649009580

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Subject: Change to network interface naming on new installs

Hi all,

Due to an oversight [[1]], network interfaces (NICs) on Fedora CoreOS are currently named using the kernel's default scheme (ethN). Depending on the order that devices are discovered, these names can change from boot to boot.

Starting with next week's Fedora CoreOS testing release, new installs will apply the predictable NIC naming scheme [[2]] used in other Fedora Editions and other Linux distributions. This change will promote to the stable stream the week of July 13. NIC names on existing systems will not change, as upgrades will automatically add "net.ifnames=0" to the kernel command line.

If you deploy Fedora CoreOS using an Ignition config that references NICs by name, you'll need to update your config to reflect the new naming. Also, if you have a mixed fleet of older and newer Fedora CoreOS installs, note that NIC names may not be consistent across machines.

--Harry Q. Bovik

[1]: https://github.com/coreos/fedora-coreos-tracker/issues/484
[2]: https://www.freedesktop.org/software/systemd/man/systemd.net-naming-scheme.html