> ## 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.

# Link Aliases

> Learn how to provide alternative names for network interfaces.

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 />

Talos Linux by default names physical network interfaces based on [predictable interface naming conventions](../predictable-interface-names) (e.g., `ens3`, `enp0s31f6`, etc.).
In some scenarios, it might be desirable to provide alternative, more user-friendly names for network interfaces.
This can be achieved using [LinkAliasConfig](../../reference/configuration/network/linkaliasconfig) configuration documents.

Note:

* only physical links can be aliased (logical links like bridges, bonds, or VLANs are given user-defined names directly);
* link alias configuration document should match exactly one physical link, otherwise the configuration will not be applied;
* link alias can be used interchangeably with physical link names in all networking configuration sections (links, routes, addresses, etc.).

The link alias is built using a CEL expression running on the specfication of a `LinkStatus` resource:

```yaml theme={null}
# talosctl get linkstatus enp0s2 -o yaml
...
spec:
    altNames:
        - enxb6dce1a4a634
    index: 8
    type: ether
    linkIndex: 0
    flags: UP,BROADCAST,RUNNING,MULTICAST,LOWER_UP
    hardwareAddr: b6:dc:e1:a4:a6:34
    permanentAddr: b6:dc:e1:a4:a6:34
    broadcastAddr: ff:ff:ff:ff:ff:ff
    mtu: 1500
    queueDisc: pfifo_fast
    operationalState: up
    kind: ""
    slaveKind: ""
    busPath: "0000:00:02.0"
    driver: virtio_net
    driverVersion: 1.0.0
    productID: "0x1000"
    vendorID: "0x1af4"
    product: Virtio network device
    vendor: Red Hat, Inc.
    linkState: true
    speedMbit: 4294967295
    port: Other
    duplex: Unknown
```

The following example creates a link alias `net0` for the only physical network interface found on the system:

```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
```

The following example creates a link alias `mgmt` for the network interface with a specific MAC address:

```yaml theme={null}
apiVersion: v1alpha1
kind: LinkAliasConfig
name: mgmt
selector:
    match: mac(link.permanent_addr) == "00:1a:2b:3c:4d:5e"
```

The aliases can be observed in the `LinkStatus` resources:

```bash theme={null}
$ talosctl get links
NODE         NAMESPACE   TYPE         ID          VERSION   ALIAS   TYPE       KIND     HW ADDR                                           OPER STATE   LINK STATE
172.20.0.2   network     LinkStatus   enp0s2      4         net0    ether               b6:dc:e1:a4:a6:34                                 up           true
...
```

In the above example, the physical interface `enp0s2` has been aliased to `net0`, which can now be used in all networking configuration sections.

To see all aliases produced from the machine configuration, use the following:

```bash theme={null}
$ talosctl get linkaliasspec
NODE         NAMESPACE   TYPE            ID       VERSION   ALIAS
172.20.0.2   network     LinkAliasSpec   enp0s2   1         net0
```