Notizen:
IPsec was developed for IPv6 in the beginning but can be deployed based on IPv4 too.
IPsec implements the authentication and encryption of all IP based protocols. In the past the application protocols were secured using security layers like SSL. When using IPsec this is not required anymore, because the encryption already takes place at the network layer.
This universal encryption of all IP based protocols allows the usage of IPsec for the setup of virtual private networks. Almost all vendors implement their virtual private network products based on this protocol.