IPv4 And IPv6 Network Interconnection Of The Project Design And Implementation

October 2009, China Internet Information Center released a report:As of the end of September 2009, the scale of China's Internet users reached 338 million. So in 2009 the number of China's online population than the USA, even more than the absolute number of users ranks first in the world. IPv4 addresses, but only 73,650,432, the gap is quite large. IPv6 is the case of a good solution, but to solve the IPv6 and IPv4 interoperability problems.This paper summarizes the existing program and its transition based on the scenarios, a pure for pure IPv6 nodes and IPv4 nodes transparently communicates. The system through the use of NAPT-PT with the agency as the way will be sent to IPv6 packets into IPv4 format address and port, also check and adjust the portion and the source address and port and converted new address and port records to the address mapping table. Address mapping table using the hash table plus linked list of the design and use LRU algorithm to find. When the response packets to return, in accordance with the hash values map to quickly find addresses, replace the address and port back to the original. At the same time, the proxy server is responsible for all the links in the page address transformation, and thus to achieve a transparent proxy to visit the website. That is, when the user points to open links on any Web page, you can go directly to the proxy server to recover, instead of repeat the previous process. This is designed to function through the modular system to achieve the program's high cohesion low coupling, and up to improve overall system performance. The overall performance of the system basically reached the expected goal, and be innovative. That is to first retrieve the content from the web page link on all collected and redirected so that users do not have time to even the NAPT-PT server, reducing the load.The system from function to meet needs. Through the lab environment to test the system operation, reaches the desired results. But the speed to be improved.