Network

systemd-networkd

Network Configuration

Create a file named <something>.network, eg 20-eth0.network, in /etc/systemd/network/.

[Match]
Name=eth0

[Network]
DHCP=yes

You can specify multiple interfaces as well:

[Match]
Name=eth0
Name=eth1

[Network]
DHCP=yes

with static address:

[Match]
Name=eth0

[Network]
Address=10.1.10.9/24
Gateway=10.1.10.1
DNS=10.1.10.1

Restart the service systemctl restart systemd-networkd.

More information in the archlinux wiki

MAC Address Randomization with systemd.link file

The following configuration will randomize the MAC addresses of the matched interfaces on boot time (does not work when just restarting systemd-networkd).

Create a something.link file in /etc/systemd/network/, e.g. /etc/systemd/network/90-all.link. The name starts with 90... because I set the "default" for the interfaces. Quote from manpage:

The first (in alphanumeric order) of the link files that matches a given interface is applied, all later files are ignored, even if they match as well.

So, the default will be to randomize the MAC address as shown in the next configuration block, but I could create another link file starting with number below 90, which would take precedence at any time, e.g. if I wanted to create a static spoofed MAC address and not a randomized one. (I'm already taking precedence with my custom .link file. Take a look at the /usr/lib/systemd/network/99-default.link file.)

Content of /etc/systemd/network/90-all.link:

[Match]
# Mach all interfaces with:
OriginalName=*
# one or more explicit hardware MAC addresses where this configuration should match
#PermamentMACAddress=aa:bb:cc:dd:ee:ff 12:34:56:78:90:ab

[Link]
#MACAddress=<fixed-spoofed-mac>
MACAddressPolicy=random

See man systemd.link (5).

This works for the ethernet interface. As I'm using iwd for WLAN, see the next section, which is a simple 3-line configuration.

MAC Address Randomization with iwd

This configuration randomizes the MAC address at every (re)start of iwd (Internet wireless daemon) to prevent tracking by WLAN providers.

Put the following in /etc/iwd/main.conf:

[General]
AddressRandomization=once
AddressRandomizationRange=full

If you want to generate a MAC address for every network, which will be consistent accross restarts of iwd as well, use AddressRandomization=network. This will generate a new MAC for every network and it will always be the same MAC for the same network. The option full randomizes all 6 octets of the MAC address (other option is nic). See man iwd.config (5).

In interfaces file

Edit /etc/network/interfaces.

With DHCP

auto eth0
iface eth0 inet dhcp

With static address

auto eth0
iface eth0 inet static
address 10.0.3.3
netmask 255.255.255.0
gateway 10.0.3.1
dns-nameservers 9.9.9.9

See also linuxhint.com

Tethering via iPhone

Connect the iPhone via USB and make sure that USBGuard allows the connection if you use it.

A new interface should show up with a name such as enp0s20f0u1c4i2. If that's not the case you can try running sudo idevicepair pair to pair the iPhone.

Create a systemd-networkd config in /etc/systemd/network/30-tethering.network with the following content:

[Match]
Name=enp0s20f0u1c4i2

[Network]
DHCP=yes

This will automatically pick up the new interface and get an IP address via DHCP.