Point to Point Protocol Extensions Working Group (PPPEXT ) (Popularity: ): An IETF group working on PPP's extensions. PPTP Crack (Popularity: ): Counterpane Systems has exposed insecurities in Microsoft's Point to Point Tunneling Protocol. Point to Point Tunneling Protocol (Popularity: ): PPTP technical specification by 3Com. Layer 2 Tunnelling Protocol Daemon (L2TPd) (Popularity: ): History and information on this Protocol. PoPToP (Popularity: ): PPTP server solution for Linux. Includes downloads, documentation and news. PPTP Client (Popularity: ): A Linux, FreeBSD and NetBSD client for the Microsoft Point-to-Point Tunneling Protocol. VPN-Protocols (Popularity: ): Technologies used for creating secure VPNs. Various standards and protocols listed with links to related RFCs.