Caot coect to VirtualBox internal network

I have been trying to coect two virtual machines on VirtualBox via the inteal network that they have. I have done a fresh install of Ubuntu 14.04, and i have set up the DHCP server using the command:

VBoxManage dhcpserver add --netname intnet0 --ip 192.168.66.1 --netmask 255.255.255.0 --lowerip 192.168.66.2 --upperip 192.168.66.255 --enable

When i change the adapter to "inteal network" and start the machine, it is unable to coect to the network. A message telling me i have been discoected constantly pop-ups. And when i type in 'ifconfig' to the terminal the ip address is not given? How can i resolve this?