NetworkManager is a daemon that sits on top of libudev and other Linux kernel interfaces (and a couple of other daemons) and provides a high-level interface to network interface configuration and setup and is accessible via dbus to apps.
How it works
NetworkManager is a software utility that aims to simplify the use of computer networks on Linux-based and other Unix-like operating systems.
The device drivers for hardware network interfaces, are typically part of the operating system kernel. User space tools such as ifconfig or ip (from the iproute2-bundle) are used to configure the addresses and other characteristics of these network interfaces. Traditionally, during the operating system startup process, programs such as System V init or systemd have run shell scripts or other programs which configure the network interfaces based on fixed information from the host's configuration files.
However, dynamic configurations (i.e., not stored in a static configuration file but taken from outside the host, and potentially changing after boot) have been an increasingly more common configuration, especially as we've moved from physically large servers to more portable hosts that may be plugged and unplugged (or moved from WiFi hotspot to WiFi hotspot) at the will of the user. Bootp was an early protocol used for this, and to this day its descendant DHCP is still very common. Many Unix-like systems include a program called dhclient to handle this dynamic configuration.
Given a relatively static or simple dynamic configuration, static configuration modified by dhclient works well. However, as networks and their topologies get more complex, a central manager for all the network configuration information becomes more essential.
History
Red Hat initiated a NetworkManager project in 2004 with the goal of enabling Linux users to deal more easily with modern networking needs, particularly wireless networking. NetworkManager takes an opportunistic approach to network selection, attempting to use the best available connection as outages occur, or as the user roams between wireless networks. It prefers Ethernet connections over “known†wireless networks, which are preferred over wireless networks with SSIDs to which the user has never connected. The user is prompted for WEP or WPA keys as needed.
The NetworkManager project was among the first major Linux desktop components to utilize D-Bus and HAL extensively. Since June 2009, however, NetworkManager no longer depends on HAL, and since 0.9.10 (ca. 2014), neither does it require the D-Bus daemon to be running for root operation.
Software architecture
NetworkManager has two components:
- the NetworkManager daemon, the actual software which manages connections and reports network changes
- several graphical front-ends for diverse surfaces, such as GNOME Shell, GNOME Panel, KDE Plasma Workspaces, Cinnamon, etc.
Both components are intended by the developers to be reasonably portable, and the applet is available to desktop environments which implement the Freedesktop.org System Tray Protocol, including GNOME, KDE Plasma Workspaces, Enlightenment (software) and Xfce. As the components communicate via D-Bus, applications can be written to be “link-awareâ€, or to replace the provided applet entirely. One example is KNetworkManager, a KDE frontend to NetworkManager developed by Novell for SUSE Linux.
Graphical front-ends and command line interfaces
-
- nm-applet
- the GNOME applet for NetworkManager.
- nmcli
- built-in command-line interface (added in 2010)
- nmtui
- built-in text-based user interface (incomplete).
- cnetworkmanager
- command-line interface for NetworkManager.
Mobile broadband configuration assistant
Antti Kaijanmäki announced the development of a mobile broadband configuration assistant for NetworkManager in April 2008; it became available in NetworkManager version 0.7.0. Together with the package mobile-broadband-provider-info the connection is easily configured.
See also
- Linux on the desktop
- BlueZ
- GNOME Keyring Manager
- UMTSMON
- usbserial
- Wicd Network Manager written in Python
- wicked tool and library provides a new, experimental framework for network configuration, GPLv2, created 2010-09-13
- wpa_supplicant
- wvdial
- netifd a tiny daemon with the ability to listen on netlink events; does not require D-Bus, does not depend on GLib, targets embedded devices
- ConnMan - connection manager is a daemon for managing Internet connections within embedded devices
- wifi-switcher simple frontend to command-line utilities (iwlist, ifup, ifdown, isc-dhcp-server, wpa_supplicant, hostapd). Automatically connects to available wireless networks according to priorities. Creates ad-hoc wireless hotspot with ftp server. To be used either with IceWM or in terminal via pdmenu.
References
External links
- NetworkManager Homepage
- Service Provider Database
- NetworkManager in freedesktop.org
- NetworkManager status on the freebsd-gnome mailing list
- Original NetworkManager page at redhat.com via WaybackMachine
- Introducing NetworkManager
- Announcement of the first public release of NetworkManager
- How to use a WiFi interface with NetworkManager