I want to setup monowall behind an existing firewall to provide VPN  
access for users to all LAN resources. I just want monowall to act as  
a vpn server and let the firewall currently in place do the filtering.  
Is this possible with monowall? My current setup is a very basic one:

DSL modem with static IP block -> Linksys running DD-WRT -> switch ->  
servers
WAN IP block					192.168.1.x range

Where would I place the monowall? What would the WAN and LAN  
interfaces be? What would the monowall PPTP config look like? Does  
anyone know of a good VPN resource for more of a vendor neutral  
explanation of VPNs, their placement and configuration?

Many thanks,
Trevor