To apply configuration changes in NetworkManager, which command is used?

The command nmcli con reload is used to apply configuration changes in NetworkManager by reloading the connection configurations without having to restart the entire service. This command specifically targets the connections managed by NetworkManager, allowing for a more efficient and seamless update of network settings.

When you invoke this command, it reads the configuration files again and applies any changes made to them. This is particularly useful in scenarios where you have made changes to connection settings (like IP addresses, routes, or DNS) in the relevant configuration files. It enables users to apply these changes without any noticeable interruption to the network services.

In contrast, restarting the entire NetworkManager service or the network service itself, while sometimes necessary for a complete reset or as a troubleshooting step, is more disruptive and not always required just to update connection settings. These methods would typically involve dropping all active connections temporarily, whereas the nmcli con reload command focuses solely on updating the configurations in a non-disruptive manner.