> ## Documentation Index
> Fetch the complete documentation index at: https://docs.siderolabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Predictable Interface Names

> How to use predictable interface naming.

export const VersionWarningBanner = () => {
  const latestVersion = "v1.13";
  const [latestUrl, setLatestUrl] = useState(null);
  const [currentVersion, setCurrentVersion] = useState(null);
  const [isBeta, setIsBeta] = useState(false);
  const parseVersion = v => v.replace("v", "").split(".").map(Number);
  const isGreaterVersion = (a, b) => {
    const [aMajor, aMinor] = parseVersion(a);
    const [bMajor, bMinor] = parseVersion(b);
    if (aMajor > bMajor) return true;
    if (aMajor === bMajor && aMinor > bMinor) return true;
    return false;
  };
  useEffect(() => {
    if (typeof window === "undefined") return;
    const {pathname, hash, search} = window.location;
    const match = pathname.match(/\/talos\/(v\d+\.\d+)\//);
    if (!match) return;
    const detectedVersion = match[1];
    if (detectedVersion === latestVersion) return;
    setCurrentVersion(detectedVersion);
    if (isGreaterVersion(detectedVersion, latestVersion)) {
      setIsBeta(true);
    }
    const newPath = pathname.replace(`/talos/${detectedVersion}/`, `/talos/${latestVersion}/`);
    setLatestUrl(`${newPath}${search}${hash}`);
  }, []);
  if (!latestUrl || !currentVersion) return null;
  return <div className="not-prose sticky top-6 z-50 my-6">
      <div className="border border-yellow-500/30 bg-yellow-500/10 px-4 py-3 rounded-xl">
        <div className="text-sm">
          {isBeta ? <>
              ⚠️ You are viewing a <strong>beta version</strong> of Talos ({currentVersion}).
              This version may be unstable.
              <a href={latestUrl} className="ml-2 underline text-yellow-400 hover:text-yellow-300 font-medium">
                View latest stable version {latestVersion} →
              </a>
            </> : <>
              ⚠️ You are viewing an older version of Talos ({currentVersion}).
              <a href={latestUrl} className="ml-2 underline text-yellow-400 hover:text-yellow-300 font-medium">
                View the latest version {latestVersion} →
              </a>
            </>}
        </div>
      </div>
    </div>;
};

<VersionWarningBanner />

Starting with version Talos 1.5, network interfaces are renamed to [predictable names](https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/)
same way as `systemd` does that in other Linux distributions.

The naming schema `enx78e7d1ea46da` (based on MAC addresses) is enabled by default, the order of interface naming decisions is:

* firmware/BIOS provided index numbers for on-board devices (example: `eno1`)
* firmware/BIOS provided PCI Express hotplug slot index numbers (example: `ens1`)
* physical/geographical location of the connector of the hardware (example: `enp2s0`)
* interfaces's MAC address (example: `enx78e7d1ea46da`)

The predictable network interface names features can be disabled by specifying `net.ifnames=0` in the kernel command line.
Please note that `eth0`, `eth1`, etc. naming scheme is not stable across reboots and can change based on the order of device discovery, so it is not recommended to use it in production environments
when multiple network interfaces are present.

> Note: Talos automatically adds the `net.ifnames=0` kernel argument when upgrading from Talos versions before 1.5, so upgrades to 1.5 don't require any manual intervention.

"Cloud" platforms, like AWS, still use old `eth0` naming scheme as Talos automatically adds `net.ifnames=0` to the kernel command line.

## Single network interface

When running Talos on a machine with a single network interface, predictable interface names might be confusing, as it might come up as `enxSOMETHING` which is hard to address.
There are two ways to solve this:

* disable the feature by supplying `net.ifnames=0` to the initial boot of Talos, Talos will persist `net.ifnames=0` over installs/upgrades.
* use [link aliases](./configuration/aliases):

  ```yaml theme={null}
  apiVersion: v1alpha1
  kind: LinkAliasConfig
  name: net0
  selector:
      match: true # as there is a single link only, we can match it this way
  ```