Notizen:
The Internet is based on the protocol suite TCP/IP. The basic protocol is the Internet protocol IP. All transfers using the Internet are based on IP via TCP, UDP, ICMP etc.
When IP was developed the prime goal was the implementation of a robust routable protocol useful in a packet switched network. The protocol was supposed to be capable to to discover the best route from point A to point B. Security was not an issue at that time.
Todays need of authentication and encryption was not understood. Therefore IP does not offer any mechanisms to ensure the authentication, integrity or confidentiality of the data. Numerous attacks like IP spoofing and session hijacking are possible.
IPsec now offers a seamless transparent protocol extension and fills the gap.