VPN enumeration
In this section, we will discuss discovering and testing the Virtual Private Network (VPN) systems.
Several years ago, when a branch office wanted to connect to the head office, it needed to set a dedicated network line between the branch and head offices. The main disadvantage of this method was the cost; a dedicated network line is expensive.
A VPN allows a branch office to connect to the head office using the public network (Internet). The cost of using a public network is much cheaper than using a dedicated line. With the VPN, the branch office will be able to use the application in the headquarters as if the branch office is located in the Local Area Network (LAN). The connection established is protected by encryption.
Based on the method used, VPN can be divided into at least three groups:
IPsec-based VPN: This type is a popular VPN solution for connecting the branch office to the head office's LAN. The branch office will install an IPsec VPN client on the network gateway...