从IPv4向IPv6的过渡

Transition from IPv4 to IPv6

目前,IPv6及相关协议已经相对成熟。然而,IPv4网络向IPv6网络的过渡和互通仍然是个艰巨的任务,直接影响了IPv6的发展。本文在对现有的各种互通与过渡方案进行综合分析的基础上,针对目前转换与互通中所存在的问题,提出了一种穿透NAT实现IPv6终端互连的隧道机制。该机制可以支持所有常见的NAT类型,无需特殊的IPv6地址前缀,可以向用户提供固定的IPv6地址。另外,针对IPv6网络和IPv4网络间的信息交互的不断增加,而基于通用处理器的IPv4/IPv6转换网关很难满足性能需求的现状,基于专用网络处理器平台研发了高性能的IPv4/IPv6转换网关,在IPv4与IPv6网络间实现了高性能的地址和协议转换,为IPv4网络向IPv6网络的平滑升级提供了保证。

Although the details of IPv6 protocol are reaching maturity, the transition from IPv4 to IPv6 is a great challenge. Based on the analysis and experiments, we provide solutions that resolve the transition problems. Firstly, classic tunneling methods do not work when the IPv6 candidate node is isolated behind a NAT device. We propose here a mechanism, called Silkroad, to enable nodes located behind one or several IPv4 NATs to obtain IPv6 connectivity. It can provide IPv6 connectivity through all existing NAT types and does not need special IPv6 addressing prefix. In addition, Silkroad does not require any update of the NAT devices and can provide the users with permanent IPv6 addresses. Secondly, ordinary translation gateway based on general processors can not satisfy the high performance requirement of high speed IPv6/IPv4 communication. Based on network processors, we design and implement high performance IPv4/IPv6 translation gateways, which could provide guarantee for efficient communication between IPv6 and IPv4 network.