- OpenVPN – OpenVPN is an open source software application that implements virtual private network (VPN) techniques for creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It uses a custom security protocol that utilizes SSL/TLS for key exchange.
- SoftEther VPN – Among the many features of this open source VPN the most important one is the Dynamic DNS; which helps to avoid using a fixed IP for the DNS server. By turn this improves security, and helps to reduce the usage of fixed-IP addresses throughout your sesssion.
- FreeLAN – It supports both peer-to-peer and client-server architecture alongside a hybrid mode. FreeLAN works on all Linux flavors, Windows, and Mac.
- strongSwan – Supporting IKEv1 and IKEv2 and with a lot of features especially the Dead Peer Detection (DPD) which helps solving the problem of dangling tunnels.
- Pritunl – Although this VPN has some features that are not completely free, an experienced system administrator would get by on the free and open source version.
- WireGuard – Any Linux server out there can be used to deploy a VPN server using WirdGuard thanks to the kernel module already shipped in it since 5.6.