Ubuntu Server and Ubuntu Desktop use different network managers. Ubuntu Server uses networkd which doesn’t have a GUI component. So after adding a desktop to Ubuntu Server you won’t be able to see or change the configuration via the GUI by default.
|Ubuntu Desktop||Ubuntu Server|
For you to be able to see the network settings on the GUI you need to switch from networkd to NetworkManager.
apt install network-manager network-manager-gnome network-manager-openvpn network-manager-openconnect network-manager-openvpn-gnome
Check which systemd network daemons are active:
systemctl list-unit-files | grep -i network
Disable/stop networkd services:
systemctl disable systemd-networkd.service systemctl disable networkd-dispatcher.service systemctl stop systemd-networkd systemctl stop systemd-networkd.socket systemctl stop systemd-networkd.service systemctl stop network-dispatcher.service
Remember that nmcli can be used for CLI NetworkManager control also.
Network interfaces are listed in yaml files in /etc/netplan/
Edit /etc/netplan/50-cloud-init.yaml and edit the line or add a line after the version: 2 entry to be renderer: Networkmanager.
network: ethernets: eno1: dhcp4: true version: 2 renderer: NetworkManager
Check the changes and apply them:
netplan generate netplan try / netplan apply