No IP address for eth0 Ubuntu 16.04

I cannot obtain an IP address for eth0 on Uuntu 16.04. I’m connected to the router.

This is what I get from ifconfig:

 eth0      Link encap:Ethernet  HWaddr 00:e0:4c:69:e0:b3                 inet6 addr: 2a01:388:350:111::1:17/128 Scope:Global               inet6 addr: fe80::d92b:2c51:626e:202f/64 Scope:Link               UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1               RX packets:372 errors:0 dropped:0 overruns:0 frame:0               TX packets:48 errors:0 dropped:0 overruns:0 carrier:0               collisions:0 txqueuelen:1000                RX bytes:48359 (48.3 KB)  TX bytes:9200 (9.2 KB) 

In /etc/network/interfaces i have this:

auto lo iface lo inet loopback