Why VirtualBox assigns the same IP address to two instance of VMs? Both use Host-only networking

Sorry for a lot of noise in the question.

Basically it is what happened:

1) I use only one network adaptor (NAT) when I first created both VM

2) I then added one more Host-only adaptor in VirtualBox and expecting, incorrectly, the new interface will appear in ifconfig

Solution to my issue

Add the new eth1 in the /etc/network/interface and restart network.

If you have created a clone from one that you have already created, check the MAC address of both the installations.

If the MAC addresses are the same, change the MAC address on one of the machines and restart it.