he package ifupdown and so /etc/network/interfaces are no longer used. Ubuntu 17.10 Server uses the package netplan instead, which configures systemd-networkd.
Make sure you use the default content for the config file /etc/network/interfaces
# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
# Generated by debian-installer.
# The loopback interface
iface lo inet loopback
And create this netplan config file for a static IPV4 address (works for me): /etc/netplan/01-netcfg.yaml .
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
Make sure you use the correct network interface name ("ens3" in this example).
Make sure you use the correct DNS servers (nameservers->addresses) for your network environment.
Once this file has been created, run the following commands as root to test & activate the configuration:
sudo netplan --debug generate
sudo netplan apply