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What's New in NetworkManager

The Right Settings

Article from ADMIN 74/2023

By Thorsten Scherf

The current version of NetworkManager introduces some changes to this de facto standard for configuring the network stack on Linux. We look at the configuration changes you need to make to keep the network running smoothly.

The vast majority of Linux distributions use NetworkManager [1] as the standard tool for configuring the network stack. Even though the systemd-networkd daemon [2] has been a popular alternative for some time, many administrators still appreciate the flexibility that NetworkManager offers. The tool is especially convenient when you use a laptop and switch between different wireless local-area networks (WLANs). Besides a graphical tool that includes an applet for the desktop, you also can configure the service from the shell. This feature also lets you automate the entire network environment setup in the server environment.

ifcfg Files

NetworkManager has always been configured with interface configuration (ifcfg) files. The files contain simple instructions for configuring a network device or more complex profiles for specific network connections. For most Linux distributions, these files are located in the /etc/sysconfig/network-scripts/ or /etc/network/interfaces directory. Ultimately, the plugin you use decides which files NetworkManager accesses – but more about that later. If you are unsure, you can discover the path to the configuration files with the command:

nmcli -f TYPE,FILENAME,NAME conn
TYPE wifi
FILENAME /etc/sysconfig/network-scripts/ifcfg-GrandHotel_Guest
NAME GrandHotel_Guest

A trivial example that configures an Ethernet card named enp0s31f6 as a DHCP client would be:

TYPE=Ethernet
DEVICE=enp0s31f6
BOOTPROTO=dhcp

Listing 1 shows a complete profile for a WLAN connection set up for a network interface card named wlp0s20f3 . The individual configuration options can be found in the

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