Virtual private networks can be divided into several types:
Remote entry
Connecting a computer to a local area network is analogous to a host-to-network configuration. This type allows users to connect to an enterprise network, such as an intranet. This could be used for remote workers who require access to private resources, or to allow a mobile worker to access critical tools without exposing them to the public Internet.
Site-to-site
Two networks are linked by a site-to-site configuration. This configuration connects offices that are geographically separated, or connects a group of offices to a data center installation. The interconnecting link could be run over a different intermediate network, such as two IPv6 networks connected via an IPv4 network.
Extranet-based site-to-site communication
The terms intranet and extranet are used to describe two distinct use cases in the context of site-to-site configurations.
An intranet site-to-site VPN describes a configuration in which the sites linked by the VPN are all part of the same organization, whereas an extranet site-to-site VPN connects sites from different organizations.
Individuals typically use remote access VPNs, whereas businesses use site-to-site connections for business-to-business, cloud computing, and branch office scenarios. Despite this, these technologies are not mutually exclusive and may be combined in a significantly complex business network to enable remote access to resources located at any given site, such as an ordering system located in a data center.
VPN systems can also be classified as follows:
The tunneling protocol that is used to tunnel traffic
The tunnel's termination point, for example, on the customer or network provider edge
The type of connection topology, such as site-to-site or network-to-network.
The levels of security available
Layer 2 circuits or Layer 3 network connectivity are examples of OSI layers that they present to the connecting network.
The number of concurrent connections 