IPSec的基本思想就是利用认证、加密等方法在IP层为数据传输提供一个安全屏障。虽然我们可以在TCP/IP协议中的任何层次实现认证与加密,但许多安全协议都是在IP层次上实现的,如PGP、SSH安全远程登录以及SSL在Socket层实现安全功能。 在IP层而不是其他层实现数据通讯安全具有更多的优点。IPSec就是在 The basic idea of ​​IPSec is to use authentication, encryption and other methods to provide a security barrier for data transmission at the IP layer. While we can implement authentication and encryption at any level in the TCP / IP protocol, many security protocols are implemented at the IP level such as PGP, SSH Secure Telnet, and SSL for security at the Socket level. There are many advantages to implementing data communication security at the IP layer rather than at other layers. IPSec is here