Virtual private network

A virtual private network (VPN) is a mechanism for creating a secure connection between a computing device and a computer network, or between two networks, using an insecure communication medium such as the public Internet. A VPN can extend a private network (one that disallows or restricts public access), in such a way that it enables users of that network to send and receive data across public networks as if the public networks' devices were directly connected to the private network. The benefits of a VPN include security, reduced costs for dedicated communication lines, and greater flexibility for remote workers. VPNs are also used to bypass internet censorship. Encryption is common, although not an inherent part of a VPN connection. A VPN is created by establishing a virtual point-to-point connection through the use of tunneling protocols over existing networks. A VPN available from the public Internet can provide some of the benefits of a wide area network (WAN). Virtual private networks may be classified into several categories: Remote access A host-to-network configuration is analogous to connecting a computer to a local area network. This type provides access to an enterprise network, such as an intranet. This may be employed for remote workers, or to enable a mobile worker to access important tools without exposing them to the public Internet. Site-to-site A site-to-site configuration connects two networks. This configuration expands a network across geographically disparate offices, or connects a group of offices to a data center installation. The interconnecting link may run over a dissimilar intermediate network, such as two IPv6 networks connected over an IPv4 network. Extranet-based site-to-site In the context of site-to-site configurations, the terms intranet and extranet are used to describe two different use cases. An intranet site-to-site VPN describes a configuration where the sites connected by the VPN belong to the same organization, whereas an extranet site-to-site VPN joins sites belonging to multiple organizations.