I use ubuntu 16.04. I configured interfaces file for static ip as follows:
ubu@ubuntu16:~$ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto enp0s3 # iface enp0s3 inet dhcp iface enp0s3 inet static address 192.168.0.205 network 192.168.0.0 netmask 255.255.255.0 gateway 192.168.0.1 dns-nameservers 192.168.0.1 8.8.8.8 ubu@ubuntu16:~$