说明：  ipv6还是一个比较新兴的技术，网络上资料是少之又少，本书比较详细的介绍了ipv6技术，对ipv6开发和维护的人员都会有很大帮助。
(Ipv6 technology is a relatively new technology, the information of ipv6 in internet is extremely rare, this book describes in more detail ipv6 technology. It is very helpful to the development and maintenance of ipv6, I think.)