Abstract:

In the IPv4/IPv6 transition process, since some legacy IPv4 networks still need to communicate with the IPv6 Internet, the stateless communication mechanism between an IPv4 network and the IPv6 Internet, which complements the current IPv4/IPv6 translation framework, was proposed. First, the communication procedures in two related scenarios were demonstrated. The two scenarios include IPv6 Internet clients accessing IPv4 servers and IPv4 clients accessing IPv6 Internet servers. The one-way IPv6-IPv4 address mapping function is the key component of the mechanism. Therefore, the requirements and three quantitative criteria of the one-way mapping function were discussed. Afterwards, multiple Hash functions as the candidates of the one-way mapping function were compared and analyzed with the real user data of large IPv6 websites and real IPv6 server addresses. The simulation results show that the FarmCity Hash function is suitable to be deployed in the above two scenarios because it has short average processing time, low collision rate and low reverse query complexity. It also verifies the validity of the stateless communication mechanism. Compared with current stateful communication mechanisms, the stateless mechanism has better scalability and traceability. Moreover, the capacity for bidirectional communication facilitates a smooth migration path towards the IPv6 Internet.

Key words: IPv4/IPv6 transition, stateless translation, Hash function, scalability, traceability

摘要：

在IPv4/IPv6过渡进程中,针对一些尚未升级到IPv6的IPv4网络仍需要与IPv6互联网互联互通的问题,提出了一种无状态的双向通信机制,完善了目前IPv4/IPv6翻译的整体框架。首先,针对IPv4服务器被IPv6用户访问的场景和IPv4网络访问IPv6资源的场景分别提出了相应的通信流程,结合已有的无状态通信机制,形成统一的IPv4/IPv6无状态通信框架。其次,对IPv6到IPv4的单向映射函数的需求进行了分析,提出了三个定量评价标准,并用实际数据对各种哈希函数进行了分析和比较。实验表明,FarmHash哈希算法的处理时间短、冲突频率低、反向查询复杂度低,适合用于IPv4网络与IPv6互联网相互通信的两类场景,从而验证了该机制的可行性;与现有的有状态通信机制相比,该机制具有很好的可扩展性和可溯源性,能够支持双向发起的通信,因此可以有效促进IPv4到IPv6的过渡。

关键词: IPv4/IPv6过渡, 无状态翻译, 哈希函数, 可扩展性, 可溯源性