OpenVPN is software that implements virtual private network (VPN) techniques to create secure point-to-point or site-to-site connections in routed or bridged configurations and remote access capabilities.
It uses a custom security protocol that uses SSL/TLS for key exchange. It is able to traverse network address translators (NATs) and firewalls. OpenVPN allows peers to authenticate using username/password, certificates, or a pre-shared secret key. It also allows the use of two-factor authentication.
It can be used to securely connect a remote location, such as an office, to a central location, such as a data center, allowing all connected devices to communicate securely with each other.
OpenVPN is highly configurable, easy to set up and use, and can be used in a variety of applications including Site-to-Site VPNs, Remote Access VPNs, and Road Warrior VPNs.
It is also compatible with a variety of VPN gateway devices such as Cisco, Juniper, Check Point and others.