A Virtual Private Network (VPN) is a private network which extends through a process of encapsulation and in some cases of encryption, from the data packets to different remote points. Data packets of private network travel through a tunnel defined in the public network.
In case of remote access, VPN allows the user to access their corporate network, assigning their remote computer’s addresses and privileges. Sometimes, it may be interesting that the communication that travels through the tunnel established in the public network is encrypted to allow greater confidentiality.
The main advantage of using a VPN is that it allows us to enjoy a network connection with all the characteristics of the private network that we want to access. VPN client fully acquires the network, applying all the security guidelines and permissions of a computer on that private network. In this way, you can access the information published for that private network i.e. databases, internal documents, etc. All Internet access connections from VPN client computer will be carried out with the resources and connections that the private network has.
Among the disadvantages we can mention a greater load on the VPN client, since it has to perform additional task of encapsulating data packets once again. This situation is aggravated when, in addition, it is done with data encryption which produces a greater slowdown of the majority of connections. There is also a greater complexity in data traffic, which can produce undesirable effects in forwarding the numbering assigned to VPN client and which may require changes in application or program configurations.
The use of encryption in the VPN connection may be necessary in cases where the information that is going to pass through the tunnel is sensitive and requires privacy. The encrypted VPN connection requires sufficient resources, both to the tunnel server and to the VPN client computer, besides requiring the installation of special programs to the client.
Remember that many applications and many programs already do encryption, and when they do, the VPN tunnel does not give us additional security. There are applications such as secure mail read through the secure web interface, which is safe enough not to require additional encryption, apart from the encryption between the server and the application and the client itself making the connection absolutely safe throughout the process. In a secure VPN connection, encryption takes place only between the tunnel server and VPN client and the connection between the tunnel server and the application server is done without encryption.