I currently have a Server 2008 server at the office and a Server 2008 R2 server at a Data Center. Both have RRAS installed for PPTP VPN access.
The office server is behind a router, is there a way to have the office RRAS server (or router) connect persistently to the Data Center VPN server so I can create a trust?
Have a look at persistent demand-dial connections for Routing and Remote Access Service )(RRAS). Beware that installing RRAS on a domain controller will make it multihomed (which can introduce fun minor issues-- RAS adapter being registered in DNS, NetBIOS master browser hijinks) and Microsoft recommends against multihoming domain controllers.
