The Research In The Transition Mechannism Of IPv4/IPv6

With the rapid development of Internet, the widely used IPv4 protocol has exposed a lot of faults since we began using IPv4 protocol in the 1970s, such as the shortage of IP address and the lacking of the security. To solve the problems thoroughly, the IETF (Internet Engineer Task Force) had put forward and designed the IPv6 protocol ,the next generation network protocol. It has one hundred and twenty eight bits address, which can effective solve the shortage of IP address. Besides it, IPv6 protocol takes many new technologies, which includes the more highly effective IP header and QoS and the automatic configuration of host address;all these characters greatly satisfy the needs of the users and leads to the inevitable transition from IPv4 to IPv6.The current Internet network is based on the IPv4 protocol and still has lots of the IPv4 hosts and network equipments, so it needs costly and hugely to rapidly complete the transition from IPv4 to IPv6. Also with the rising severity of network security, we have to consider the security problems in the transition process. By combining the transition with the security problems, it has the important academic and practice meaning for us to implement the fluent and seamless and secure transition from IPv4 to IPv6.The thesis firstly describles the significance, target, and the current status of the research. In the second section we analyse and compare the IPv4 and IPv6 protocol, particularly emphasis on the IPv6 protocol. We analyse and compare some transition mechanisms presently, and especially focus on the tunnel mechanism in the third section. In the fourth section we discuss the IPSec protocol in detail and analyse all kinds of models. By building the experimental environment, we implement some kinds of familiar transition mechanism based on combining the IPSec protocol and validate the feasibility and security by the IPv4/IPv6 transition testing flat in the fifth section, which is developed by me indepently. At last, we get access to the IPv6 Internet by using the Tunnel Broker system based on the proxy.