Chapter 2. Getting started with NetworkManager

By default, RHEL uses NetworkManager to manage the network configuration and connections.

2.1. Benefits of using NetworkManager

The main benefits of using NetworkManager are:

  • Offering an API through D-Bus which allows to query and control network configuration and state. In this way, networking can be checked and configured by multiple applications ensuring a synced and up-to-date networking status. For example, the RHEL web console, which monitors and configures servers through a web browser, uses the NetworkManager D-BUS interface to configure networking, as well as the Gnome GUI, the nmcli and the nm-connection-editor tools. Each change made in one of these tools is detected by all the others.
  • Making Network management easier: NetworkManager ensures that network connectivity works. When it detects that there is no network configuration in a system but there are network devices, NetworkManager creates temporary connections to provide connectivity.
  • Providing easy setup of connection to the user: NetworkManager offers management through different tools — GUI, nmtui, nmcli.
  • Supporting configuration flexibility. For example, configuring a WiFi interface, NetworkManager scans and shows the available wifi networks. You can select an interface, and NetworkManager displays the required credentials providing automatic connection after the reboot process. NetworkManager can configure network aliases, IP addresses, static routes, DNS information, and VPN connections, as well as many connection-specific parameters. You can modify the configuration options to reflect your needs.
  • Maintaining the state of devices after the reboot process and taking over interfaces which are set into managed mode during restart.
  • Handling devices which are not explicitly set unmanaged but controlled manually by the user or another network service.

2.2. An overview of utilities and applications you can use to manage NetworkManager connections

You can use the following utilities and applications to manage NetworkManager connections:

  • nmcli: A command-line utility to manage connections.
  • nmtui: A curses-based text user interface (TUI). To use this application, install the NetworkManager-tui package.
  • nm-connection-editor: A graphical user interface (GUI) for NetworkManager-related tasks. To start this application, enter nm-connection-editor in a terminal of a GNOME session.
  • control-center: A GUI provided by the GNOME shell for desktop users. Note that this application supports less features than nm-connection-editor.
  • The network connection icon in the GNOME shell: This icon represents network connection states and serves as visual indicator for the type of connection you are using.