Types of VPNs
There are many VPN products available on the market, both commercial and open source. Almost all of these VPN products can be separated into the following four categories:
- PPTP-protocol based VPNs
- IPSec-protocol based VPNs
- SSL-based VPNs
Some people argue that OpenVPN is also an SSL-based VPN, as it uses an SSL or TLS-like protocol to establish a secure connection. However, we have created a separate category for OpenVPN, as it is different from almost every other SSL-based VPN solution.
We will now go into more detail about each of the four types of VPNs:
One of the oldest VPN protocols is the Point-to-Point Tunneling Protocol (PPTP) developed by Microsoft and Ascend in 1999. It is officially registered as RFC2637 (see https://www.ietf.org/rfc/rfc2637.txt ...