Connectivity among different Virtual Machines

Question

I have a VirtualBox installed on my Host OS Ubunut 11.04. (64-bit)

I have 4 virtual machines installed all of them in turn Ubunutu 11.04 (64-bit)

I want all the 4 machines to be a part of the single network and I need connectivity among them.I do not want connectivity with other machines on the host's physical network or even to the host's network adapter.

What network mode should I configure the machines in.I have tried the different options on Virtual Box.I have written a simple ping test which does a ping from one VM to all the other three

1) NAT Mode - ping test fails 2) Bridged Adapter - ping test succeeds.But I get packets (ICMP packets captured using libpcap) from strange IP addresses.I am assuming those machines are a part of the host's network.I want to avoid this.Is there any way by which I can achieve that.

Answer 1

You should attach your machines to the VirtualBox Internal network.

To quote from the chapter 6 of VirtualBox user manual.

Internal Networking is similar to bridged networking in that the VM can directly communicate with the outside world. However, the "outside world" is limited to other VMs on the same host which connect to the same internal network.

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.

Alternatively you can use

 VBoxManage modifyvm "VM name" --nic<x> intnet

Optionally, you can specify a network name with the command

 VBoxManage modifyvm "VM name" --intnet<x> "network name"

Answer 2

I am more familiar with Vmware and HyperV but you can set a network adapter to host only. You can create a private network that the guests can communicate with the hosts. According to this (http://www.virtualbox.org/manual/ch06.html) you can do the same on virtualbox.

I use it on a few a my VMs to back them up.