I've tried setting up a VPN server on my Windows 2008 R2 virtual server using the steps outlined in the following link: http://dubravkomarak.wordpress.com/2012/07/18/configuring-vpn-connection-on-server-2008-r2-using-rras-and-configuring-clients/
Unfortunately, at the last step of the RRAS setup wizard, when it implements the changes made, I lost internet connection to the server. I requested a power cycle on the server and the server eventually became accessible again when it rebooted. Unfortunately, it only remained so for a few minutes and then I lose all internet connectivity to it. I rebooted the server again and during the few minutes window I had, I uninstalled the RRAS role from the server. Unfortunately, the server still suffered from the same problem: I can only access it for a few minutes after it reboots, after which I lose all internet connectivity to it.
Any thoughts on how to resolve the problem?