IP version 4 (IPv4) has been a core part of the TCP/IP protocol suite and has served well during tremendous growth of the Internet. IPv4, mostly called just IP, defines addressing and routing for most corporate networks that use TCP/IP as well as the public Internet. Though IPv4 has been a long-time companion, it has its shortcomings that created the need for a protocol that could replace IPv4. That protocol is Internet Protocol version 6 or IPv6 for short. IPv6 defines the same general functions that are defined by IPv4. However, there are differences in detail that we will explore in this chapter.
//IPv6 Introduction