virtualbox portable firewall/proxy
 

Using virtualbox under Windows is there a way to configure a firewall/proxy Linux distro such as CentOS so that all Windows web traffic first goes through the firewall and then out to the network using just a single wireless NIC?
In other word, I'd like to use my portable on public wifi and carry the proxy with me in a virtual machine. This way my laptop can enjoy the benefits of a web proxy and firewall anywhere. I suspect the solution is to have two NICs in the VM one for bridged so that CentOS can communicate directly with the wireless NIC and one for NAT so that the Windows host can communicate into the VM then through the VM to the Internet.
I appreciate any thoughts.

Rather than using one NAT NIC and one Bridged Adapter NIC, you could use one NAT NIC and one Host-Only Adapter NIC. You could use the first (NAT) to access the Internet, while the other would end up in the internal VirtualBox network, and would be reachable via the VirtualBox Host-Only Adapter in Windows (which defaults to 192.168.56.1/24).

The advantage with this approach is that the VM does not depend on any external service. If you use a bridged adapter, the VM will need to obtain an IP address via DHCP, and you won't be able to tell in advance what that IP address will be.

Excellent. Your solution is simpler and equally effective. Thanks.