Following are the protocols used to encrypt a virtual private network (see
VPN).
OpenVPN
Very popular, OpenVPN is a unique VPN protocol that runs on every platform. It uses the OpenSSL library, which offers strong 256-bit encryption. Because it runs on SSL port 443, it defeats VPN blocking. OpenVPN also supports dynamic IP addresses at both ends of the connection. It can also be added to the router.
L2TP/IPsec
Layer 2 Tunneling Protocol - IP Security
L2TP provides the tunneling, while IPsec does the authentication and encryption. Offers respectable security and performance if the AES encryption is selected rather than 3DES. L2TP is easily blocked because it uses only a few ports (see
IP port).
SSTP - Secure Socket Tunneling Protocol
A Microsoft protocol mainly for Windows, SSTP is not easily blocked because it uses a standard SSL 443 port, but it does use the older SSL security protocol.
PPTP - Point-to-Point Tunneling Protocol
An early and rather vulnerable protocol. Good for unblocking location-blocked websites.
IKEv2/IPsec
Internet Key Exchange Version 2/IP Security
The latest VPN protocol but not available on popular operating systems.