[Help] Routing Between Two Virtual Machines

[benynug]

Greetings,

I am new in configuring Virtual Machines, and I have a problem in routing between two virtual machines.

Here is my system :
Host : Windows 7 64-bit
VB 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.

[noteirak]

Well if you can connect to the router machine, it means Virtualbox is working properly.. anything like routing and the sort should be asked on a networking forum, as this is way out of scope of this forum.
Most likely : the NAT interface interfers with your routing table -- you're missing the routes -- firewall is blocking -- routing is not enable in your router VM (not enabled by default)

[benynug]

Well if you can connect to the router machine, it means Virtualbox is working properly.. anything like routing and the sort should be asked on a networking forum, as this is way out of scope of this forum.
Most likely : the NAT interface interfers with your routing table -- you're missing the routes -- firewall is blocking -- routing is not enable in your router VM (not enabled by default)

I tried disabling NAT, the result is even the Host 1 can not ping the Router, it said "unreachable".
How to enable routing in my router VM?

Thanks

[noteirak]

I am afraid I must insist :

anything like routing and the sort should be asked on a networking forum, as this is way out of scope of this forum.