If you are genuinely interested in answer to this question, you will like the below eBook that answers that question fabulously. http://www.internetsociety.org

If you are genuinely interested in answer to this question, you will like the below eBook that answers that question fabulously. http://www.internetsociety.org/deploy360/blog/2013/12/free-ebook-ipv6-for-ipv4-experts-in-english-and-russian/ http://www.internetsociety.org/deploy360/blog/2013/12/free-e... It's free, very high quality content, and it is written as if you co-design the new IP protocol together with the author - you start from "why" and arrive to "how".