I run Windows 2008 Server HyperV so that I can deploy my primary SBS 2008 Server, and also to host various test servers. In testing another SBS server, you can set up a Virtual Private Network. However, one of the challenges is to expose this server to the live network to simulate a real world environment using a router.
Vyatta (www.vyatta.com) produces an Open Source network appliance which can be configured as a router to bridge the Virtual Private Network to the Live Network, thus creating a real life scenario for the test environment.
The main download for the product is Vyatta Core 6.0 LiveCD which can be downloaded here as an ISO – http://www.vyatta.com/downloads/swdl.php
All the documentation for the product can be found here – http://www.vyatta.com/downloads/docdl.php
I will blog shortly about how to set up the Router in a hyperV.