VPN fundamentals

By definition, a VPN is a connection that enables a remote user to securely connect to a private network or server over a public network. From the end user's perspective, it is as if the data is being sent and received over a dedicated private connection—hence, the term virtual private network. One common scenario in which a VPN is used is called client-server: the end user connects to a private network over the internet. Another common scenario is peer-to-peer, or network-to-network communication. A prime example of this would be a case where a branch office of a corporation needs to connect its local network with the private network at corporate headquarters. In such a case, the company is using the internet as if it is a WAN. In either case, client-server or peer-to-peer, the end users of the VPN take advantage of the fact that a VPN connection...