A Virtual Private Network (VPN) allows the provisioning of private network services for an organization or organizations over a public infrastructure, such as the Internet, instead of with physical wires. The network is said to be "virtual" because it links two "physical" networks (local area networks) using an unreliable connection (the Internet), and "private" because only computers that belong to a local area network on either end of the VPN can "see" the data. The technologies introduced today are applied to IP-based VPNs rather than frame relay or ATM networks.

OpenVPN is one of the virtual private network (VPN) solutions that establish secure tunnels between host computers. Two networking techniques are supported by OpenVPN: Ethernet bridging and IP routing. Moxa provides a ready-to-run OpenVPN middleware to enable Moxa embedded computers to be used as OpenVPN gateways with IP routing capability.

Internet Protocol Security (IPsec) is a suite of protocols for securing Internet Protocol (IP) communications by authenticating and/or encrypting each IP packet in a data stream. IPsec protocols provide a set of security services to create secure channels between a pair of security gateways, such as a router or a firewall. Since IPsec provides reliable encryption, integrity, authentication, and replay protection, adding IPsec to Moxa's embedded computers helps prevent threats from intruders.

Openswan is an implementation of Internet Protocol Security (IPsec) for Linux platforms. Moxa provides Openswan configuration examples for integrators who want to use RSA (Asymmetric key cryptography) and PSK (Symmetric key cryptography) authentication algorithms to create host-to-host, subnet-to-subnet, or host-to-subnet IPsec connections.