Research And Realization On IPv6Rapid Deployment

IPv4as a cornerstone protocol of the Internet technology has been widely used.But due to IPv4has some shortcomings, such as limited address space, the routingefficiency is not high enough, the lack of service quality and safety, which seriouslyrestrict the future network development. With the development of the IPv6, IPv6willoccupy IPv4cornerstone status by virtue of its superior performance. As thebackbone network of Internet Service Provider still dominated by IPv4and peoplecan’t stand the network suspend, we need a scheme which has cost less to realize thecommunication of IPv6sites under the existing IPv4network architecture in a shorttime. IPv6rapid deployment(6RD) is such a scheme.This paper first presents the importance of IPv6, then aim at the communicationof scattered IPv6networks studies three familiar IPv4to IPv6transition techniqueswhich are double-stack, translation and the tunnel. After that, we analyse theadvantages, disadvantages of these three technologies, and then spread the study of6RD automatic tunnel’s design and realization. Specific research contents and themain work is as follows.Firstly, based on the principle of6RD automatic tunnel mechanism, we studiedand designed6RD tunnel through adopt of vxWorks embedded operating system asthe system development environment, Wuhan Fiberhome network limited liabilitycompany’s high-end router as a development platform, Wind River’s Tornado as thedevelopment environment. Focus analyze destination address mapping algorithm of6RD tunnel, encapsulation of6RD, the character of automatic tunnel.Secondly, In the process of realization, we send data flow which destinationaddress of tunnel interface matched static route to CPU process. CPU generated routecorrespondingly for each different data streams dynamically and calculateddestination address of tunnel. Implementation of the6RD automatic tunnel throughthese under the condition of chip does not support the6RD automatic tunnel. Andthrough the kernel calls the GTF timer, timed monitor IPv6router table entry whetherthere is flow of data match the route. If there is no data flow through, deleted route entry dynamically. Thereby accomplished the aging of6RD tunnel route.Thirdly, designed6RD overall scheme, the realization of the hardware andsoftware environment based on vxWorks operating system. Then designed datastructures, the software module, wrote and debugged6RD program on the basis ofoverall plan. The software module design can be divided into initialization module,transmit-receive module, routing management module and configuration module.Initialization module completed the allocation of memory, registration of hookfunctions and so on. Transmit-receive module presented specific packet transmit andreceive process. Routing management module realized the addition and aging of route.Configuration commands are list in configuration module.Finally, this paper designed test plan and test platform for testing or verfying thefunctions and performances. Functional tests including IPv6prefix agent and addresscheck in domain test, basic communication test between equipments, support bothIPv4and IPv6based business and application test. Performance testing including thethroughput test, forwarding delay test and overload packet loss rate test. The testresults meet the design requirements.