Physical Links

Learn how to configure physical network interfaces.

Configuration

Physical network interfaces (links) can be configured in Talos Linux using the LinkConfig 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:

apiVersion: v1alpha1
kind: LinkConfig
name: enp0s3
mtu: 9000
up: true

Link aliases can also be used to refer to physical links in a more user-friendly way:

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 documentation.

Observing status

Use talosctl to observe the status of all links:

$ 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:

$ 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:

$ 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