"I'd never heard of Dual DHCP DNS Server before seeing it above. I had tried Tiny DHCP server and it wasn't doing what I wanted. I had tried VirtualBox's built-in DHCP server too. Dual Server did exactly what I wanted with very little fuss. Now I have a VirtualBox Host-Only Network where all my VM guests can talk w/ each other and with my VM host machine- but which cannot possibly communicate with anything outside of my host machine. AND now, because of Dual Server, I can now do everything using regular hostnames. There's not a fixed IP address anywhere in the new setup. Dual server really worked well for me.
For those who are interested in VirtualBox, my Guest VM setup has two NICs- the first one gets the VBox default NAT subnet, and the second one gets my Vbox Host-only network. If I want the guest VM's to be able to get out to the internet for OS updates or whatever, I just connect the virtual ethernet cable on the first NIC. My Vbox Host-only network's built-in DHCP server is DISABLED, so that Dual Server can do the work. Dual Server runs on my host machine and I bound it to the (static) IP address of the Vbox Host-only network."
