I have a virtualbox lab made up of 4 Windows 2008 R2 servers (DC/DNS,SQL,SHAREPOINT, EXCHANGE) that are configured with static ip addresses with NIC's attached to Internal network. Everything works.

I had the requirement to execute some tests that also access external services available on the internet. To keep things clean and similar to the production environment I have installed another VM, with Ubuntu Server 12.04 64 bit and configured (I hope) to work as a router like described on this post.

This VM has two network interfaces: first is Bridged with the host and is used as a WAN connection and the other one attached in the Internal Network with its own static IP address on the internal network subnet.

But actually the Windows servers does not connect to the internet while the unix one connects.

I did a route command. this is the result:

Kernel IP Routing table
Destination       Gateway        Genmask         Flags   Metric  Ref     Use   Iface
default           10.69.121.1    0.0.0.0         UG      100     0         0   eth0
10.69.121.0       *              255.255.255.0   U       0       0         0   eth0
192.168.83.0      *              255.255.255.0   U       0       0         0   eth1

Can somebody help me with this configuration? :) Thanks!

Addendum: I forgot to mention that one of the windows server hosts a DNS service for which I should maybe configure a forwarding server but I do not exactly know which server to forward on... :(