What is OpenVPN?

With OpenVPN, you can:

• 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 on Windows or Mac OS X.