I'm thinking about setting up a security testing lab. I work on a switched network, and that just makes for unnecessary headaches when doing testing.

I'd like to create a 192 network with a few machines inside for DBs and AppServers etc. I will need a pivot machine that connects to both the outer network and the 192 (for automation purposes). But I'd like to be able to connect into the 192 network with my own machine from the outer network as the "attacking" machine (rather than have dedicated attack machines inside the 192 network). Therefore, I'd like to have the pivot server be a VPN server as well, so that my machine can VPN into the 192 network from the outer network.

First off, is this even possible? Can I have a single computer with two NICs where a VPN service allows remote connections into the 192?

Secondly, I'd like to have multiple outer clients connect to the VPN. Does anyone have any suggestions? I've used Hamachi well before, but I've also seen some good stuff from OpenVPN.