Analysis And Implementation Of NAT-PT In IPv6 Network Transition

With the prevalence of Internet, new challenge appears to the version 4 protocol of internet. The most urgent problem is exhaust of IPv4 addresses. It makes people to invent new standard of internet protocol which is used by the next general network. IPv6 standard solved many problems, including the exhaust issue.The actuality of the network and problems are analysis in this paper. Several solutions which are used normally are all listed. NAT-PT and other related technologies are researched in detail; the main idea is connecting IPv6 nodes and IPv4 nodes via the middle converting gateway. The gateway can change IP header between IPv4 and IPv6 so that the message can be passed through different structure network. NAT-PT gateway is implemented in the paper. Beside the basic function of gateway, DNS-ALG is added to work, in order to convert the domain name query. The combine of the two modules finish the process of ICMP and DNS conversion. Meanwhile the gateway can create and delete the session records dynamically. It gives the gateway more power to deal the traffic, which make gateway more excellent.After finish the implement, test is done during the two type of network. Detail analysis about the whole process of session is given out. It achieves the purpose of the initial design of the gateway. It connects the two type of network.