IPv6 Transition Strategy

With the currently rapid development of the Internet, there appears a growing tendency that the use of addresses based on the IPv4 network protocol is becoming scarcer, so the IETF(The Internet Engineering Task Force) proposed to replace IPv4 with IPv6 protocol agreement. IPv6 has such new features as mass addresses, multicast, neighbors discovery, and auto configuration. But, how to achieve the smooth transition from IPv4 to IPv6 and how to construct IPv6 network based on IPv4 network remain a problem.This thesis gathers some relevant materials on the IPv6 protocol and IPv4/IPv6 transition at home and abroad, focuses on the new IPv6 features, analyzes and compares the three commonly used methods of transition: double-stack technology, tunnel technology and address translation. In our campus, double-stack technology and ISATAP tunnel technology are mainly used, but both cannot traverse NAT. Though Microsoft came up with teredo tunnel technology as a solution, this technology has many defects, such as too many devices involved, complex disposition and inability to traverse symmetrical NAT.In view of these problems, this thesis advances a new solution based on Client / Server technology for traversing NAT. This new technology needs only less equipment and greatly facilitates users. Besides, a client software for common users with different connecting mode is designed, thus sparing users from any demand operations; they can conveniently connect to IPv6 network by clicking on the button.