4.1. Virtual Private Network (VPN)

A virtual private network (VPN) is a communication tunnel that provides point-to-point transmission of both authentication and data traffic over an intermediary untrusted network. Most VPNs use encryption to protect the encapsulated traffic, but encryption is not necessary for the connection to be considered a VPN. VPNs are most commonly associated with establishing secure communication paths through the Internet between two distant networks.

VPNs can exist anywhere, however, including within private networks or between end-user systems connected to an ISP. The VPN can link two networks or two individual systems. VPNs can link clients, servers, routers, firewalls, and switches. VPNs are also helpful in providing ...

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