ubuntu 16.04 network

root@ubuntu:~# ls /sys/class/net/
enp0s3  enp0s8  lo


root@ubuntu:~# vim /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 
auto enp0s8 
iface enp0s8 inet dhcp