I created a Ubuntu server on virtualbox that Ubuntu server install with minimal virtual machine. I created the three linked clone and I have internal network between them. I removed 70-persistent-net.rules. I see this output when I run ifconfig:
eth0 Link encap:Ethernet HWaddr 08:00:27:e6:72:8a inet6 addr:fe80::a00:27ff:fee6:728a/64 Scop:Link . . .
I cannot see IPv4 address. I need an IPv4 address. How do I get this?