Bug 2190375

.NetworkManager notifies when using the deprecated `ifcfg` format Connection profiles in `ifcfg` format are deprecated in RHEL 9 (see xref:BZ-1894877[]). With this update, NetworkManager notifies users about the deprecation of this format: * NetworkManager logs the following warning to the `systemd` journal if it processes a connection profile in `ifcfg` format in the `/etc/sysconfig/network-scripts/` directory: + ---- Warning: the ifcfg-rh plugin is deprecated, please migrate connections to the keyfile format using "nmcli connection migrate" ---- * The `nmcli` utility reports the following error if you try to modify a property that is not supported in `ifcfg` format: + ---- Error: Failed to modify connection '<name>': failed to update connection: The ifcfg-rh plugin doesn't support setting '<property>'. If you are modifying an existing connection profile saved in ifcfg-rh format, please migrate the connection to keyfile using 'nmcli connection migrate <connection_uuid>' or via the Update2() D-Bus API and try again. ---- As a result of these enhancements, NetworkManager now notifies users if they still use or modify connection profiles in the deprecated `ifcfg` format. For further details about migrating profiles from `ifcfg` to keyfile format, see link:https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/configuring_and_managing_networking/assembly_networkmanager-connection-profiles-in-keyfile-format_configuring-and-managing-networking#proc_migrating-networkmanager-profiles-from-ifcfg-to-keyfile-format_assembly_networkmanager-connection-profiles-in-keyfile-format[Migrating NetworkManager profiles from ifcfg to keyfile format].