摘要： 介绍了IPv6 与IPv9 的起源和特点，并在地址空间和域名服务、移动的支持性、内置的安全特性、QoS、自动配置、应用范围和支持者，以及发展可能性和发展趋势等几个方面，对二者加以比较，分析其优劣所在。指出IPv9 不是IPv6 的升级版本，而是IPng 的一个建议版本，尚未被接受为国际标准。在民用互联网中，IPv6 无疑是主流标准；在军事网和部分政府网络中，从国家安全的角度出发，IPv9可能争得一席之地。

关键词: IPv6；IPv9；标准；IETF

Abstract: This paper introduces the origination and characteristics of IPv6 and IPv9, and compares them in several aspects, such as address space and domain name service, mobility support, built-in security features, QoS, auto-configuration applications and sponsors, etc. The paper then analyzes their adoption and evolution trends. It points out that IPv9 is not an upgraded version of IPv6, but an alternative candidate of the next generation IP, and is not yet accepted by IETF as an Internet standard. The paper suggests that IPv6 inevitably be applied in commercial networks, while IPv9 could have a chance to be accepted by military networks and some government networks because of the consideration in national security.

Key words: IPv6; IPv9; Standard; IETF