How to Fix systemd-networkd DHCPv6 Lease Issue on Debian 10 and Above

Learn how to solve the problem of systemd-networkd not being able to find org.freedesktop.network1 when using DHCPv6 on Debian 10 and above.

Problem

If you are using systemd-networkd to manage your network interfaces on Debian 10 or above, you may encounter an error message like this when trying to use DHCPv6:

systemd-networkd[1234]: Could not acquire DHCPv6 lease on eth0: No such interface 'org.freedesktop.network1'

This means that systemd-networkd is unable to communicate with the networkd D-Bus API, which is required for DHCPv6 functionality. In this article, we will explain why this happens and how to fix it.

Why systemd-networkd Cannot Find org.freedesktop.network1

The reason why systemd-networkd cannot find org.freedesktop.network1 is that the networkd D-Bus API is not enabled by default on Debian 10 and above. This is because Debian uses a different implementation of D-Bus than upstream systemd, which is called dbus-broker. dbus-broker is more secure and efficient than the original D-Bus daemon, but it also requires explicit configuration of the services that are allowed to use it.

By default, Debian does not include systemd-networkd in the list of allowed services for dbus-broker, which means that systemd-networkd cannot access the networkd D-Bus API. This is a known issue that has been reported to the Debian bug tracker, but it has not been resolved yet.

How to Enable networkd D-Bus API on Debian 10 and Above

To enable the networkd D-Bus API on Debian 10 and above, you need to do two things:

1. Install the systemd-networkd-dbgsym package, which contains the networkd D-Bus service file.
2. Add systemd-networkd to the list of allowed services for dbus-broker.

Step 1: Installing systemd-networkd-dbgsym

The systemd-networkd-dbgsym package is not available in the official Debian repositories, but it can be installed from the Debian debug repository. To do this, you need to add the following line to your /etc/apt/sources.list file:

deb http://debug.mirrors.debian.org/debian-debug/ buster-debug main

Replace buster with the codename of your Debian release, such as bullseye or sid. Then, run the following commands to update your package list and install the systemd-networkd-dbgsym package:

sudo apt update
sudo apt install systemd-networkd-dbgsym

This will install the networkd D-Bus service file to /usr/lib/systemd/system/org.freedesktop.network1.service.

Step 2: Adding systemd-networkd to the Allowed Services for dbus-broker

To add systemd-networkd to the list of allowed services for dbus-broker, you need to create a configuration file in /etc/dbus-1/system.d/ with the following content:

<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <policy user="root">
    <allow own="org.freedesktop.network1"/>
    <allow send_destination="org.freedesktop.network1"/>
    <allow receive_sender="org.freedesktop.network1"/>
  </policy>
</busconfig>

You can name the file anything you want, as long as it ends with .conf. For example, you can name it networkd.conf. This file will grant root permission to own, send, and receive messages from the networkd D-Bus service.

After creating the file, you need to restart the dbus-broker service and the systemd-networkd service with the following commands:

sudo systemctl restart dbus-broker.service
sudo systemctl restart systemd-networkd.service

This should enable the networkd D-Bus API and allow systemd-networkd to use DHCPv6 on your network interfaces.

Frequently Asked Questions (FAQs)

Question: How do I check if the networkd D-Bus API is working?

Answer: You can use the busctl command to list the available D-Bus services and check if org.freedesktop.network1 is among them. For example, you can run the following command:

busctl --system list

This will show you a table of the D-Bus services and their properties. If you see org.freedesktop.network1 in the table, it means that the networkd D-Bus API is working.

Question: How do I check the DHCPv6 lease information from systemd-networkd?

Answer: You can use the networkctl command to show the DHCPv6 lease information for your network interfaces. For example, you can run the following command:

networkctl status eth0

This will show you the status of the eth0 interface, including the DHCPv6 lease information, such as the address, prefix, DNS, and NTP servers. You can also use the -a option to show the status of all network interfaces.

Question: How do I configure systemd-networkd to use DHCPv6 on my network interfaces?

Answer: You need to create a network configuration file in /etc/systemd/network/ with the following content:

[Match]
Name=eth0

[Network]
DHCP=ipv6

Replace eth0 with the name of your network interface. This file will tell systemd-networkd to use DHCPv6 on the eth0 interface. You can also use other options to customize the DHCPv6 behavior, such as UseDNS, UseNTP, or RapidCommit. For more details, see the systemd.network man page.

Summary

In this article, we have learned how to fix the systemd-networkd DHCPv6 lease issue on Debian 10 and above. We have explained why systemd-networkd cannot find org.freedesktop.network1, and how to enable the networkd D-Bus API by installing the systemd-networkd-dbgsym package and adding systemd-networkd to the allowed services for dbus-broker. We have also shown how to check the DHCPv6 lease information and configure systemd-networkd to use DHCPv6 on our network interfaces.

Disclaimer: This article is for informational purposes only and does not constitute professional advice. The author and the publisher are not liable for any damages or losses that may result from following the instructions or using the information in this article. Always consult a qualified IT professional before making any changes to your system or network configuration.