Greetings,

I hope I put this question in correct forum since I am working with Ubuntu in my VirtualBox. I am new in configuring Virtual Machines (VMs), and I have a problem in routing between two guests with Ubuntu 12.04 run on both.

Here is my system :
My Host : Windows 7 64-bit
VirtualBox version : 4.2.12
All of my 3 guests : Ubuntu 12.04

My VM configuration is as the following :
VM1 - As a Host 1
Adapter 1 : NAT
Adapter 2 : Host-Only, the IP address is 192.168.56.101

VM2 - As a Router
Adapter 1 : NAT
Adapter 2 : Host-Only, the IP address is 192.168.56.102
Adapter 3 : Host-Only, the IP address is 192.168.194.101

VM3 - As a Host 2
Adapter 1 : NAT
Adapter 2 : Host-Only, the IP address is 192.168.194.102

I want it to make it like this : VM1 <---> VM2 <---> VM3.
But the ping result that I got :
from VM1 to VM2 : Success
from VM1 to VM3 : Failed!
from VM2 to VM1 : Success
from VM2 to VM3 : Success
from VM3 to VM1 : Failed!
from VM3 to VM2 : Success

It seems like the VM2 does not work as a router, it can connect to each host, but i can not make the hosts connected with each other. Can someone please help me?
Thank you.