PPTP stands for Point-to-Point Tunneling Protocol.
PPTP is a networking standard for connecting to virtual private networks(VPN). These are secure networks that can be accessed over the Internet, allowing users to access a network from a remote location. This is useful for people who need to connect to other network from a location to another location.
The “point-to-point” term refers to the connection generated by PPTP. It allows one point to access another determined point over the Internet. The “tunneling” term refers to the way one protocol/Algorithm is encapsulated within another respective one. In PPTP, the point-to-point protocol is wrapped inside the TCP/IP protocol, which provides the Internet connection. Therefore, even though the connection is created over the Internet, the PPTP connection makes a direct link between the two clients/locations, giving a secured connection. PPTP is fast due to its low level of encryption and it is capable of offering fast connectivity.
Working of a PPTP
PPTP is an improved version of PPP, on the basis of its authentication and encryption framework. Like all tunneling technologies, PPTP is used to encapsulate data, creating a route for data to flow across an IP network.
PPTP uses a client-server design that operates at Layer 2 of the OSI model. Once the VPN tunnel is established, PPTP supports two types of information flow, one is the Control messages for managing and eventually tearing down the VPN connection. Control messages pass directly between VPN client and server. The other one being Data packets that pass through the tunnel, i.e. to or from the VPN client.
PPTP uses General Routing Encapsulation, TCP port 1723, and IP port 47. PPTP supports encryption keys up to 128-bits, and it uses Microsoft Point-to-Point Encryption
The most secured versions of PPTP is to exclusively use:
- MPPE-128 encryption which uses RC4 encryption with a 128bit key.
- MS-CHAPv2 authentication which uses SHA-1.
- Strong Passwords.
Types of Tunneling:
- Voluntary Tunneling: This type of tunneling is initiated by the client, so no ISP or bridge support is required.
- Compulsory Tunneling: Since this type of tunneling is initiated by the PPTP server, router and network access server support is necessary.
Advantages of PPTP
- PPTP is a very fast VPN protocol.
- PPTP is really easy to set up and configure on most operating systems and devices.
- Due to the protocol’s high rate of cross-platform compatibility, a PPTP connection can be established on tons of platforms.
- Lower transmission costs: No additional service used, other than the Internet.
- Reduces hardware costs: Allows ISDN cards and modems to be separated from other servers, which results in fewer devices to purchase and manage.
- Low administrative overhead: Administrators only manage the remote access server (RAS) and user accounts, rather than managing different hardware configurations.
- Enhanced security: PPTP connection is encrypted and secured over the Internet and works with other networking protocols, like IP, Internetwork Packet Exchange and NetBIOS Extended User Interface (NetBEUI).
Disadvantages of PTTP
- PPTP encryption is sub-par and not suitable for securing online data and traffic. The NSA has actually cracked PPTP traffic.
- A PPTP connection can be exploited by cybercriminals with malicious attacks.
- A router with PPTP Passthrough is usually required since PPTP doesn’t natively work with NAT.
- A PPTP connection can be blocked quite easily by firewalls.