Before you begin installing PPTP, it is important that you understand the following points:
· PPTP uses Microsoft’s implementation of RAS and the Point-to-Point Protocol (PPP) to establish connections with remote computers by using dial-up lines, Ethernet networks, or token ring networks. PPP provides remote-user authentication and data encryption between the PPTP client and the PPTP server. Thus, to use PPTP you must install and configure RAS with Dial-Up Networking on both PPTP clients and PPTP servers.
· Because PPTP requires RAS and the PPP protocol, you must establish a PPP account with your ISP to use PPTP over an ISP connection to the Internet.
· PPTP uses virtual devices called VPNs. When you configure PPTP, you install and configure VPNs in RAS as if they were physical devices, just like modems.
· PPTP is installed and configured on PPTP clients and PPTP servers only. Computers on the route between the PPTP client and PPTP server do not require PPTP installation.
· A PPTP server can be placed behind a firewall on the private enterprise network to ensure that traffic in and out of the private network over the PPTP server is secured by the firewall computer. (For more information, see the document “Understanding PPTP.”)
· To ensure enterprise network security, PPTP clients must be authenticated (just like any other remote user using RAS and Dial-Up Networking) in order to connect to the private enterprise network.
· Using the Internet to establish a connection between a PPTP client and a PPTP server means that the PPTP server must have a valid, Internet-sanctioned IP address. However, the encapsulated IPX, NetBEUI, or TCP/IP packets sent between the PPTP client and the PPTP server can be addressed to computers on the private enterprise network using private network addressing or naming schemes. The PPTP server disassembles the PPTP packet from the PPTP client and forwards the packet to the correct computer on the private network.