Description¶

systemd-networkd is a system service that manages networks. It detects and configures network devices as they appear, as well as creating virtual network devices.

Certain low-level settings of physical network devices (e.g. device names and altnames) as well as the creation of SR-IOV virtual functions on physical network interfaces may be managed by systemd-udevd(8) according to the contents of systemd.link(5) files.

systemd-networkd will create "virtual" network devices (e.g. bridges and tunnels) based on the configuration in systemd.netdev(5) files, respecting the [Match] sections in those files.

systemd-networkd will manage network addresses and routes for any link for which it finds a .network file with an appropriate [Match] section, see systemd.network(5). For those links, it will flush existing network addresses and routes when bringing up the device (except when directed not to). Any links not matched by one of the .network files will be ignored. It is also possible to explicitly tell systemd-networkd to ignore a link by using the Unmanaged=yes option, see systemd.network(5).

When systemd-networkd exits, it generally leaves existing network devices and configuration intact. This makes it possible to transition from the initrd and to restart the service without breaking connectivity. This also means that when configuration is updated and systemd-networkd is restarted, netdev interfaces for which configuration was removed will not be dropped, and may need to be cleaned up manually.

systemd-networkd may be introspected and controlled at runtime using networkctl(1).

See org.freedesktop.network1(5) and org.freedesktop.LogControl1(5) for a description of the D-Bus API.

Configuration Files¶

The configuration files are read from the files located in the system network directory /usr/lib/systemd/network, the volatile runtime network directory /run/systemd/network and the local administration network directory /etc/systemd/network.

Networks are configured in .network files, see systemd.network(5), and virtual network devices are configured in .netdev files, see systemd.netdev(5).

See Also¶

networkctl(1), systemd(1), systemd.link(5), systemd.network(5), systemd.netdev(5), systemd-networkd-wait-online.service(8), systemd-network-generator.service(8), org.freedesktop.network1(5)