> ## 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.

# Physical Links

> Learn how to configure physical network interfaces.

## Configuration

Physical network interfaces (links) can be configured in Talos Linux using the [LinkConfig](https://docs.siderolabs.com/talos/v1.15/reference/configuration/network/linkconfig.md) configuration objects.

The following properties can be configured for physical links:

* MTU (`mtu`): sets the Maximum Transmission Unit for the interface (default is 1500).
* bring the link up or down (`up`): controls whether the interface is administratively up or down.

Here is an example of configuring a physical network interface with a specific MTU and bringing it up:

```yaml theme={null}
apiVersion: v1alpha1
kind: LinkConfig
name: enp0s3
mtu: 9000
up: true
```

[Link aliases](https://docs.siderolabs.com/talos/v1.15/networking/configuration/aliases.md) can also be used to refer to physical links in a more user-friendly way:

```yaml theme={null}
apiVersion: v1alpha1
kind: LinkAliasConfig
name: mgmt
selector:
    match: mac(link.permanent_addr) == "00:1a:2b:3c:4d:5e"
---
apiVersion: v1alpha1
kind: LinkConfig
name: mgmt
mtu: 9000
up: true
```

For low-level control over physical link properties, such as offloading features, refer to the [Ethernet configuration](https://docs.siderolabs.com/talos/v1.15/networking/advanced/ethernet-config.md) documentation.

## Observing status

Use `talosctl` to observe the status of all links:

```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   bond0       1                 ether      bond     3e:f0:5c:84:4b:5e                                 down         false
172.20.0.2   network     LinkStatus   dummy0      1                 ether      dummy    1e:e5:74:54:52:21                                 down         false
172.20.0.2   network     LinkStatus   enp0s2      3         net0    ether               ae:48:3d:ca:38:28                                 up           true
172.20.0.2   network     LinkStatus   flannel.1   2                 ether      vxlan    fa:1a:43:6d:23:e1                                 unknown      true
172.20.0.2   network     LinkStatus   ip6tnl0     1                 tunnel6    ip6tnl   00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00   down         false
172.20.0.2   network     LinkStatus   lo          2                 loopback            00:00:00:00:00:00                                 unknown      true
172.20.0.2   network     LinkStatus   sit0        1                 sit        sit      00:00:00:00                                       down         false
172.20.0.2   network     LinkStatus   teql0       1                 void                                                                  down         false
172.20.0.2   network     LinkStatus   tunl0       1                 ipip       ipip     00:00:00:00                                       down         false
```

The output shows all network links, their operational state, and other relevant information.

To see the list of links managed by Talos, use the following:

```bash theme={null}
$ talosctl get linkspecs
NODE         NAMESPACE   TYPE       ID       VERSION
172.20.0.2   network     LinkSpec   enp0s2   6
172.20.0.2   network     LinkSpec   lo       2
```

To see the list of link configuration broken down by configuration source, add `--namespace=network-config` flag:

```bash theme={null}
$ talosctl get links --namespace=networkconfig
NODE         NAMESPACE        TYPE       ID                     VERSION
172.20.0.2   network-config   LinkSpec   configuration/enp0s2   1
172.20.0.2   network-config   LinkSpec   default/lo             1
172.20.0.2   network-config   LinkSpec   dhcp4/enp0s2/enp0s2    1
```


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.