Ubuntu Server 18.04 LTS old Network Manager?

Nostalgic about the old ubuntu network manager?

Let's do that:
(write sudo before the command if you are not root)

Install the old network manager

apt-get update
apt-get install ifupdown

Edit the interfaces

/etc/network/interfaces

With:

allow-hotplug eth0
auto eth0
iface eth0 inet static
address x.x.x.x
netmask x.x.x.x
broadcast x.x.x.x
gateway x.x.x.x
dns-nameservers x.x.x.x

Restart the interface

ifdown --force eth0 && ifup -a

Stop and remove old network manager

systemctl stop networkd-dispatcher
systemctl disable networkd-dispatcher
apt-get purge nplan netplan.io

Set the DNS

/etc/systemd/resolved.conf
With:

[Resolve]
DNS=x.x.x.x

kreissage