netplan

Netplan is a YAML-based network configuration system used on Linux, most notably in Ubuntu. It provides an abstraction layer between user-defined networking settings and the actual backends that implement those settings, such as systemd-networkd or NetworkManager.

Netplan stores configurations in /etc/netplan/*.yaml. The YAML files describe interfaces, addresses, routes, DNS settings, and other networking parameters using a versioned syntax. A user writes the desired configuration, and the system renders backend-specific configurations by running netplan generate, followed by netplan apply to enact the changes on the running system.

Renderers determine which backend is used to implement the configuration. A netplan file can specify renderer: networkd or renderer: NetworkManager, and the choice can influence feature support and behavior. Netplan supports common networking concepts such as Ethernet interfaces, VLANs, bridges, bonds, and wireless connections, but availability of features may vary between backends. The tool also supports dynamic changes and can interact with cloud-init for automated provisioning in cloud environments.

Historically, Netplan was introduced by Canonical around Ubuntu 17.10 to replace the traditional /etc/network/interfaces approach. It aims to simplify network configuration, provide a more consistent workflow across desktop and server editions, and streamline cloud and container deployments by decoupling plan creation from backend rendering.

Typical usage involves editing a YAML file in /etc/netplan, selecting a renderer, and then running netplan generate and netplan apply to apply changes. Debugging options and logs can help diagnose issues during rendering or application.