virtualbox.org

I have setup an internal network between two Linux guests on a Windows 7 host that need to communicate through multicast. When I have a single guest running with NAT networking, it can join a multicast group without error. However, when I set up the two guests to use "Internal Network", the application throws a "failed to join multicast group" due to the "operation not supported". Am I missing an obvious step to get this working? The except gets thrown anytime the network adapter for a guest is not configured to NAT. I am using a Debian based distro (CrunchBang).

NAT will give the guests access to the Internet but they will not be able to talk to each other.

Using an intnet that has the same name, for both the guests you are trying to connect to each other, will allow them to communicate. However you need to configure VirtualBox's internal DHCP server to hand them IP addresses on the internal network, in order for the experience to be seamless. Although setting static IPs should work just as well. Follow the instructions outlined here to achieve your goal:

http://www.virtualbox.org/manual/ch08.h ... dhcpserver