VPN - Virtual Private Network

You can construct a VPN in a myriad of ways, but constructing your VPN is just your first step. After you construct the VPN, you have to troubleshoot it.

A minimal VPN implementation has a RAS PPTP server connected to the Internet, a client connected to the Internet, and a PPTP connection between the server and the client. As long as ISP service or Internet connectivity is available, clients can connect to your server or LAN from anywhere in the world. However, most VPNs aren't as simple as a connected server and client. More often, the VPN server is on a routed LAN segment, often behind a firewall, and the client connection uses an ISP network, which also employs routers and firewalls.

You can build a PPTP server as a standalone server or as a domain controller in a couple of steps: You install RAS and the PPTP protocol and configure PPTP ports the same way you configure dial-up connections. Windows NT client setup is equally straightforward: You load PPTP and configure the PPTP connection to locate the PPTP server over the Internet. With such a simple setup, you might assume that the VPN connection will function properly the first time. However, administrators spend a fair amount of time troubleshooting before they successfully deploy a new VPN.