Reviewing the IPsec Principle

The basic principle of IPsec is this: All traffic between clients, whether initiated by applications, the operating system, services, and so on, is entirely encrypted by IPsec, which then puts its own header on each packet and sends the packets to the destination server to be decrypted. Because every piece of data is encrypted, this prevents electronic eavesdropping, or listening in on a network in an attempt to gain unauthorized access to data.

Several functional IPsec deployments are available, and some of the more promising ones are actually built in to the network interface cards (NICs) of each computer, performing encryption and decryption without the operating system knowing what is going on. Aside from these alternatives, Windows Server includes a robust IPsec implementation by default, which can be configured to use a PKI certificate network or the built-in Kerberos authentication provided by Active Directory on Windows Server.