Here are some key features of "OpenVPN":

· Tunnel any IP subnetwork or virtual ethernet adapter over a single UDP or TCP port, configure a scalable, load-balanced VPN server farm using one or more machines which can handle thousands of dynamic connections from incoming VPN clients,
· Use all of the encryption, authentication, and certification features of the OpenSSL library to protect your private network traffic as it transits the internet,
· Use any cipher, key size, or HMAC digest (for datagram integrity checking) supported by the OpenSSL library,
· Choose between static-key based conventional encryption or certificate-based public key encryption,
· Use static, pre-shared keys or TLS-based dynamic key exchange,
· Use real-time adaptive link compression and traffic-shaping to manage link bandwidth utilization,
· Tunnel networks whose public endpoints are dynamic such as DHCP or dial-in clients,
· Tunnel networks through connection-oriented stateful firewalls without having to use explicit firewall rules,
· Tunnel networks over NAT,
· Create secure ethernet bridges using virtual tap devices, and
· control OpenVPN using a GUI