IPv4 &IPv6

Finally my team (Myself, Jacky and David) wrapped up on ITM final presentation on IPv6 topic to class. We touched on the current version of IPv4 has not been substantially changed since RFC 791 was published in 1981. Explain on a global utility the size of today’s Internet and the recent exponential growth of the Internet and the impending exhaustion of the IPv4 address space.
I short, Below is some sharing session about IPv4 & IPv6:
IP, the Internet Protocol, is one of the pillars which supports the Internet. Almost 20 years old, first specified in a remarkably concise 45 pages in RFC 791, IP is the network-layer protocol for the Internet.
In 1991, the IETF decided that the current version of IP, called IPv4, had outlived its design. The new version of IP, called either IPng (Next Generation) or IPv6 (version 6), was the result of a long and tumultuous process which came to a head in 1994, when the IETF gave a clear direction for IPv6.
IPv6 is designed to solve the problems of IPv4. It does so by creating a new version of the protocol which serves the function of IPv4, but without the same limitations of IPv4. IPv6 is not totally different from IPv4: what you have learned in IPv4 will be valuable when you deploy IPv6. The differences between IPv6 and IPv4 are in five major areas: addressing and routing, security, network address translation, administrative workload, and support for mobile devices. IPv6 also includes an important feature: a set of possible migration and transition plans from IPv4.
Since 1994, over 30 IPv6 RFCs have been published. Changing IP means changing dozens of Internet protocols and conventions, ranging from how IP addresses are stored in DNS (domain name system) and applications, to how datagrams are sent and routed over Ethernet, PPP, Token Ring, FDDI, and every other medium, to how programmers call network functions.
Detail, pls visit : http://www.opus1.com/ipv6/whatisipv6.html