Using a static IP address

When you install ACRN on your system following the Try using ACRN, a bridge called acrn-br0 will be created and attached to the Ethernet network interface of the platform. By default, the bridge gets its network configuration using DHCP. This guide will explain how to modify the system to use a static IP address. You need root privileges to make these changes to the system.

ACRN Network Setup

The ACRN Service OS is based on Clear Linux OS and it uses systemd-networkd to set up the Service OS networking. A few files are responsible for setting up the ACRN bridge (acrn-br0), the TAP device (tap0), and how these are all connected. Those files are installed in /usr/lib/systemd/network on the target device and can also be found under misc/acrnbridge in the source code.

Setting up the static IP address

You can set up a static IP address by copying the /usr/lib/systemd/network/50-eth.network file to /etc/systemd/network/ directory. You can create this directory and copy the file with the following command:

mkdir -p /etc/systemd/network
cp /usr/lib/systemd/network/50-eth.network /etc/systemd/network

Modify the [Network] section in the /etc/systemd/network/50-eth.network file you just created. This is the content of the file used in ACRN by default.

Edit the file to remove the line highlighted above and add your network settings in that [Network] section. You will typically need to add the Address=, Gateway= and DNS= parameters in there. There are many more parameters that can be used and detailing them is beyond the scope of this document. For an extensive list of those, please visit the official systemd-network page.

This is an example of what a typical [Network] section would look like, specifying a static IP address:

[Network]
Address=192.168.1.87/24
Gateway=192.168.1.254
DNS=192.168.1.254

Activate the new configuration

You do not need to reboot the machine after making the changes to the system, the following steps that restart the systemd-networkd service will suffice (run as root):

systemctl daemon-reload
systemctl restart systemd-networkd

If you encounter connectivity issues after following this guide, please contact us on the ACRN-users mailing list or file an issue in ACRN hypervisor issues. Provide the details of the configuration you are trying to set up, the modifications you have made to your system, and the output of journalctl -b -u systemd-networkd so we can best assist you.