I have a site currently with a router directly to internet with access-lists and no firewall, this router is configured with PPTP for remote clients to vpn in. The serial interface has a public IP, ethernet interface has a private IP. Remote clients VPN in via the public IP tied to the serial interface on the router right now. I will be swapping out the old router with a new 1800 and put in an ASA firewall behind the 1800 router. My question is, how do I keep the VPN capability for remote clients? They want VPN on the ASA instead of being on the router. That means the outside interface of the ASA must have a public IP within their range. Do I place the IP address that's currently assigned to the serial interface on the router onto fastethernet0 and leave serial interface unnumbered? Then ASA's outside interface directly connected to the router's fastethernet0?? Does the router know how to pass packets from serial to its fastethernet0 interface automatically?