systemdnetworkd

systemd-networkd is a lightweight network management daemon that is part of the systemd suite. It provides a minimal, declarative way to configure networking on Linux systems, and is commonly used on servers, containers, and embedded environments. The service runs as systemd-networkd and can be enabled or started with systemctl.

Configuration is file-based. The daemon reads settings from /etc/systemd/network and, for defaults, from /usr/lib/systemd/network. The primary file types are .network, .netdev, and .link. A .network file defines per-interface network settings such as addresses, routes, and DNS. A .netdev file defines virtual devices like bridges, bonds, VLANs, and tunnels. A .link file specifies per-link properties such as MAC address, MTU, wake-on-LAN, and other driver-specific options.

Key features include support for static addressing, DHCP for IPv4 and IPv6, and the definition of routes and DNS information. DNS can be provided directly by systemd-networkd or by integrating with systemd-resolved. The daemon can manage complex topologies, including bridges, bonds, and VLANs, and responds to kernel netlink events to apply configurations automatically.

Usage typically involves enabling the service and creating configuration files. Common steps are to create or modify .network files with appropriate [Match] sections to select interfaces, then enable the service with systemctl enable --now systemd-networkd. Administrators monitor status via systemctl and journal logs. systemd-networkd is designed to be simple and reliable for static or DHCP-based configurations, and is often favored on headless servers or environments where a lightweight, centralized networking daemon is preferred over more feature-rich desktop solutions.