A Virtual Private Network (VPN) must have a secure connection to various servers when accessing the internet. Protocols facilitate these connections. Protocols are standards that define how the VPN does its communications. They are used to offer security and faster VPN experience. There are various protocols which a VPN uses each with different strengths and weakness. We are going to look at them in this article;
This is the most widely used VPN protocol. This is because it’s secure – uses an amalgam of secure technologies and protocols, its reliable, and its open source. This means anyone can audit it for flaws and it’s also highly customizable; can be configured to work in every computing platform. OpenVPN is usually used in two versions, OpenVPN TCP and OpenVPN UDP.
- OpenVPN TCP
TCP stands for Transmission Control Protocol, TCP is a suite of internet protocols that are used for network intercommunication. When OpenVPN is used with TCP, it’s more reliable as TCP provides for error checking capabilities. As a result of reliability, OpenVPN is usually slightly slow as more latency is used for retransmission when an error occurs.
- OpenVPN UDP
UDP stands for User Datagram Protocol, it’s also a communication protocol, but unlike TCP, it doesn’t offer error checking capabilities. This makes it provide a faster VPN experience.
OpenVPN uses 256-bit key encryption. Apart from being extremely secure, the only downside of this protocol is that it needs third-party software to be compatible with most platforms.
L2TP stands for Layer 2 Tunneling Protocol while IPsec means Internet Protocol security. L2TP on its own is very fast but not secure since it has weaker encryptions. IPsec, on the other hand, is a protocol that authenticates and provides encryption for communication channels; it ensures an end to end security. For L2TP to be effective, it’s typically coupled with IPsec, and together they are stronger and faster. L2TP/IPsec has no known vulnerability but its usually blocked since it uses UDP on port 500 by default; this makes it easy to spot. L2TP is an upgrade of another protocol, PPTP (look at details below).
Internet Key Exchange version 2 is a tunneling protocol, and when coupled with IPsec, it becomes a VPN protocol. This protocol is more reliable as it establishes a reconnection when the internet drops. It’s also compatible with most mobile devices. Due to these reasons, its widely used by mobile VPNs on smartphones and sometimes its preferred than OpenVPN. It’s also very secure and offers better performance as compared to L2TP/IPsec. Its only downside, it requires third-party software to implement.
SSTP stands for Secure Socket Tunneling Protocol, and it’s a proprietary protocol owned by Microsoft. It has secure technologies similar to OpenVPN protocols and theoretically, experts say it can be better than OpenVPN if it was open source. SSTP is less susceptible to blocking, its fast, secure and easy to set up. The only downside, it’s not supported by many platforms since it’s a primary windows protocol.
PPTP stands for Point-to-Point Tunneling Protocol. Its one of the oldest VPN protocols and it’s the most common in almost every VPN. Being a VPN protocol only, PPTP it’s not secure, but it offers incredible speeds and compatible with virtually every platform. It’s not recommended to use this protocol unless the task doesn’t require any security.
Of all the protocols, most VPN providers opt using the OpenVPN protocol as its fast, secure and reliable.