IPv4 and IPv6 Coexistence – What Does That Mean?

Research on the Web to find and share the information to answer each of the following questions.

1. IPv4 and IPv6 coexistence — what does that mean?
2. Will older versions of Windows OS support IPv6?
3. What is dual-stacking as regards IPv4 and IPv6?
4. What are the standards for IPv6 addressing?
5. Is there any form of IPv6 IP address shorthand?
6. Does IPv6 require DHCP? If so, how is it different from DHCPv4?
7. What impact will different levels of users experience if they don’t adopt IPv6 in the long run?