IPv6

IPv6 is the newest generation of Internet Protocol. As of 2009, the majority of Internet traffic is IPv4, which was the first version in widespread use. Versions 1, 2, 3 and 5 have all been used in experiments, but they were not good designs and were abandoned. IPv6 is gaining more use, as it is inevitable that it will become the dominant IP within the next several years.

Why should IPv6 be used?
The very main reason IPv6 should be used is because of IPv4 address exhaustion. What this means is that there are a limited number of IPv4 addresses, and the number of unallocated (unused) addresses are quickly running out.

Let us talk numbers. To make it simple, there are 256 blocks of IPv4 addresses, and each block contains about 16 million addresses.
 * Unallocated blocks remaining: 32
 * Unallocated percentage remaining: 12%
 * Date of exhaustion: April 30, 2011

So how does IPv6 fix this? By giving us many many more addresses:
 * IPv4: 4,294,967,296
 * IPv6: 340,282,366,920,938,463,463,374,607,431,768,211,456

There are so many IPv6 addresses, that every person on earth could be using 10,000, and there would still be plenty available. It's roughly equivalent to the number of molecules in the Moon.

The brief summary is: IPv4 will be obsolete in 2 years, so let's get working on preparing for IPv6 now.

Topics

 * 6to4 addressing — How to use IPv6 right now
 * 6to4 gateway router — How to use one IPv4 address to provide non-NAT IPv6 service to up to 65,525 internal subnets.