Advances in Internet technology IPv6

IPv6 integrates and covers a variety of advanced network technologies and has good extensibility. It has become the main Network Layer protocolin the next-generation Internet. In general it takes a long period for a new protocol to be invented and then to be applied in a wide range. Now there is a wide existed user base of the current IPv4 Internet, FG applications and devices, since then it is necessary to consider how to achieve a smooth transition from IPv4 to IPv6. This article describes the Internet IPv6 transition and discusses three types of transition technologies including IPv4-based IPv6 network interconnection, IPv4/IPv6 transparent interconnection and IPv6-based IPv4 network interconnection. For the key types of transition technologies, we analyze the working mechanism, the scope of the safety, the advantages and the problems, and then make the comprehensive comparison. Since China has launched a strategic program called China Next Generation Internet (CNGI) based on IPv6-only backbone in large scale, this paper discusses the transition technology of IPv4 network interconnection based on IPv6, and discusses the future research about the transitional mechanism.