At the moment, my home network is comprised of 5 computers (3 laptops and 2 desktops), one of which is running Windows Server 2008 and works as a home repository for some of our files. We access the Internet through a Thomson TG784 router which receives two wireless connections and three wired ones, one of them passing through a switch. That said, we are not using a firewall anywhere and thus relying 100% on the route'rs firewall capabilities. We have never had any problems so far, but now I would like to set up a VPN (maybe using RRAS or OpenVPN) so that I can access computers here from outside. The problem is that I am really unsure if I should do this since it means forwarding at least one port to one computer (which would be the Windows Server 2008 one), thus opening, as far as I understand, all the network to the outside. So, my questions are indeed three:
1) Is the current setup we have adequate in terms of security, or should we be using a firewall on each computer (even without any VPN or port forwarding)?
2) Will it be safe to set up a VPN on such a network or am I risking unwanted access to the network?
2) In case I really decide to set-up the VPN, how should I configure it and the machines in the network for security?