Design And Research Of VPN Based On The IPSec Over Http Protocol Under Linux

With the rapid development of Internet, more and more diversity of networkapplications, extensive. People recognize the importance of network security. Throughthe VPN network communication technology can solve security problems, includingIPSec VPN is stable, secure known. IPSec secure network communications throughthe use of encryption and authentication technologies. But the existence of the firewalland IPSec NAT device compatibility issues, namely IPSec packets can not pass a strictfirewall port restrictions and NAT devices in the application. IPSec over Http protocolis proposed to solve this problem.In this paper, an overview of the main functions of the advantages of VPN, acommon classification, the key technologies used in VPN and VPN implementation;then IPSec system to conduct a detailed overview, including its architecture, workingprinciple, workflow systems and IPSec the SA, SP, AH, ESP and other components.IPSec is then designed and implemented the system in Linux systems. Finally IPSecpackets can not pass through strict access rules and the inability to pass through thefirewall NAT device, drawing a common method of covert communication (HTTPtunneling) through the protective wall, using HTTP packets to carry IPSec packets tothe firewall and NAT crossing, will in this way is called IPSec over Httpcommunication, its encapsulated packets called IPSec over Http protocol. And givesthe overall structure and the implementation of key modules IPSec over Http systemand set up a test environment, test verification protocol, concluded that the systemproblems.