Point-to-point tunneling protocol
Point-to-point tunneling protocol (PPTP) is a protocol for virtual private networks. A specification was published as an "informational" RFC in 1999. It has not been ratified by the IETF. The protocol is not considered as secure as other VPN protocols, such as IPsec.
PPTP is implemented as a PPP session over Generic Routing Encapsulation (GRE). Authentication is usually by MSCHAP-v2, and supplies key material for the subsequent Microsoft Point-to-Point Encryption (MPPE) applied to data packets.
PPTP uses a default port of 1723 for communicating across a network. PPTP also uses Generic_Routing_Encapsulation; forwarding port 1723 alone is not sufficient to forward a pptp connection.
External links
- Point-to-Point Tunneling Protocol (PPTP), RFC 2637, July 1999; [1]
- FAQ on PPTP from Microsoft; [2]
- FAQ on security flaws in Microsoft's implementation, Bruce Schneier, 1998; [3]
- Poptop, a PPTP Server for Linux; [4]
- PPTP Client, a Linux, FreeBSD and NetBSD client; [5]