Implementations
PPTP was the first VPN protocol that was supported by Microsoft Dial-up Networking. All releases of Microsoft Windows since Windows 95 OSR2 are bundled with a PPTP client, although they are limited to only 2 concurrent outbound connections. Microsoft Windows Mobile 2003 and higher also support the PPTP protocol. The Routing and Remote Access Service for Microsoft Windows contains a PPTP server. The Microsoft implementation uses single DES in the MS-CHAP authentication protocol which many find unsuitable for data protection needs.
Windows Vista and later support the use of PEAP with PPTP. The authentication mechanisms supported are PEAPv0/EAP-MSCHAPv2 (passwords) and PEAP-TLS (smartcards and certificates). Windows Vista removed support for using the MSCHAP-v1 protocol to authenticate remote access connections.
Linux server-side support for PPTP is provided by the PoPToP daemon and kernel modules for PPP and MPPE. The first PPTP implementation was developed by Matthew Ramsay in 1999 and initially distributed under the GNU GPL by Moreton Bay. However, Linux distributions initially lacked full PPTP support because MPPE was believed to be patent encumbered. Full MPPE support was added to the Linux kernel in the 2.6.14 release on October 28, 2005. SuSE Linux 10 was the first Linux distribution to provide a complete working PPTP client. There is also ACCEL-PPP - PPTP/L2TP/PPPoE server for Linux which supports PPTP in kernel-mode.
OS X and iOS are bundled with a PPTP client. Cisco and Efficient Networks sell PPTP clients for older Mac OS releases. Palm PDA devices with Wi-Fi are bundled with the Mergic PPTP client.
Many different Mobile phones with Android as the operating system support PPTP as well.
Read more about this topic: Point-to-Point Tunneling Protocol