How to do networking between virtual machines in VirtualBox?

I have two virtual machines in VirtualBox. I would like to do networking between them. For the moment I have the default configuration on both, but they seem to have the same IP-address 10.0.2.15. I would also like to be able to use Internet with both, and that is Possible now.

By default the network-setting is NAT, but it seems like they cannot network internally since they have the same IP. But If I change to internal networking I guess that I cannot access Internet with the virtual machines.

How can I set up networking between virtual guest AND have access to Internet on them?

Answer

Have you tried this Virtual Networking Guide ?

The virtual machine receives its network address and configuration on the private network from a DHCP server integrated into VirtualBox. The IP address thus assigned to the virtual machine is usually on a completely different network than the host. As more than one card of a virtual machine can be set up to use NAT, the first card is connected to the private network 10.0.2.0, the second card to the network 10.0.3.0 and so on.

I think what you're looking for is "Internal Networking" , connecting internal VMs each other.

You can use a VM's "Settings" dialog in the VirtualBox graphical user interface. In the "Networking" category of the settings dialog, select "Internal Networking" from the drop-down list of networking modes. Now select the name of an existing internal network from the drop-down below or enter a new name into the entry field.