Information:
PoPToP is the PPTP server solution for Linux. Ports exist for Solaris 2.6, OpenBSD and FreeBSD, among others.
To date, no real solution existed if you wanted to include Linux servers in PPTP established VPNs. PoPToP resolves that problem by allowing Linux servers to function seamlessly in the PPTP VPN environment.
This enables administrators to leverage the considerable benefits of both Microsoft and Linux.
