TDF - just saw this. For your VPN you need two nics, a public & a private. In a basic install they would be on seperate newtorks so that would eliminate your first issue but some higher end systems will allow you to load balance and add additional VPN adapters for load balance and redundancy. 'Course this adds a LOT more rules.
I try to steer away from using standard MS VPN (L2TP/PPTP) and go with IPSEC based stuff. Even open source
