Although it's a little longish, I'll post the whole notice I received.

Anyone who wants to see the pretty pictures can get to the original at Enterprise Networking: IPv6: 10 Things You Didn`t Know About Internet Protocols

Briefly - Most will be familiar with the "numerical" addresses actually used by Internet servers to communicate with each other. Our "address" at mudcat.org actually gets whipped around between servers after it's translated to something like an xxx.xx.xxx.xx "IP address."

The bottom line is that the addresses of that form, defined by IPv4 (Internet Protocol version 4) were all used up in February 2011. The only way to get "on the Internet" since then has been to find an "abandoned address" or buy one from some scalper who grabbed them to speculate with.

For IPv4, the current standard (until today)

Example IPv4 Address: 195 51 100.14
Unique Identifiers: 4,294,967,290

Only ~4 billion sites could exist.

For IPv6, the new address form:

Example IPv6 Address: 2001:D88:BE:C001:1234:ABCD:22:1
Unique Identifiers: 340,282,366,920,938,463,374,607,431,768,211,456

340 decillion sites should be enough for at least a few days.

Today (06 June 2012) is the day when everybody is supposed to "turn on" the use of the new numbers.

THIS WILL BE TRANSPARENT TO MOST INDIVIDUAL USERS NOW, but "sometime" in the future it will be impossible for servers that continue to use IPv4 addresses to communicate with servers that use IPv6.

TEXT OF THE ANNOUNCEMENT - for those of us strange enough to care:

By Darryl K. Taft on 2012-06-05

The Internet Society, an international nonprofit organization that advises on Web standards, policy and education, has selected June 6, 2012, as the World IPv6 launch day. This date will mark the beginning of a new phase in the life of the Internet, when IPv6 begins to become a normal part of the Internet experience for everyone—taking over from IPv4.

Last year, the Internet Society declared June 8, 2011, as World IPv6 Day to give enterprises and Internet service providers (ISPs) a chance to "stress test" the next-generation Internet protocol to see what works, what breaks and what they need to do to seamlessly migrate their networks to IPv6. It also served as a wake-up call that it's time to upgrade the World Wide Web.

On that day, more than 200 Web companies—including giants Facebook, Google and Yahoo—worked with ISPs and content-delivery networks to conduct the first global-scale trial of IPv6. For a 24-hour period, participating companies around the world enabled IPv6 on their main services.

Operating systems—including Apple Mac OS X, most versions of Microsoft Windows and most major Linux distributions—have supported IPv6 addresses for a number of years. In fact, since IPv6 addresses are enabled by default in the operating system, if the network has the capability to assign an IPv6 address, the user machine most likely already has an IPv6 address, James Lyne, director of technology strategy at Sophos, told eWEEK in 2011.

At some point, the entire Internet infrastructure has to move to using the newer address space, since the differences in the protocols mean that computers with IPv4 addresses cannot communicate with machines with IPv6 addresses. The Internet Society says that time is now. eWEEK takes a look at some of the key differences between IPv6 and IPv4. It also identifies some information you may not know about IPv6.

1. Difference Between IPv4 and Ipv6
Internet Protocol (IP) addresses are unique numeric identifiers needed by every Internet-connected device. Most of the Internet is currently addressed with IP version 4 (IPv4) addresses; however, IPv4 was not designed for a Global Internet with billions of users. After it became clear in the early 1990s that a global commercial Internet would emerge, the Internet Engineering Task Force (IETF) began development of a new protocol (IPv6) that would meet its needs by offering a much larger IP address pool.

2. Internet Assigned Numbers Authority (IANA)
IP addresses are assigned, managed and distributed by global, nonprofit organizations. IP addresses are managed by the Internet Assigned Numbers Authority (IANA), which has overall responsibility for the IP address pool, and by the Regional Internet Registry (RIR) Organizations to which IANA distributes large blocks of IP addresses. RIRs manage, distribute, and publicly register IP addresses within their respective regions. They do this according to policies that are developed within their respective regional communities, through open and bottom-up processes.

3. Out of IPv4 Addresses
According to the Number Resource Organization, the world officially ran out of IPv4 addresses in February 2011 when the IANA IP address pool was depleted. This means if you're interested in moving onto the Internet in its current form, you're too late. The Internet is completely full.

4. Geographic Differences
The final allocations of IPv4 to the Regional Internet Registry (RIR) Organizations will soon be depleted. Based on the current rate, the remaining IPv4 address pools held by the RIRs are likely to be depleted globally in the next few years. The Asia-Pacific region has depleted its unrestricted IPv4 resource pool and new Internet growth in the region will require transitioning to IPv6. All other regions will soon be in the same situation.

5. IPv6 Is the Successor to Ipv4
IPv6 is the successor to IPv4. The Internet will use both versions for many years, with IPv6 becoming the most utilized. It functions similarly to IPv4 in that it provides the unique, numerical IP addresses necessary for Internet-enabled devices to communicate. However, it does sport one major difference: It uses 128-bit addresses. IPv6 has significantly more address space, which makes the IP addresses look different. A typical IPv6 address has eight groups of four letters and numbers separated by colons and looks like this: 2001:DB8:BE:C001:1234:ABCD:22:1, compared with IPv4, which uses 32-bit addresses and looks significantly smaller: 198.51.100.14.

Example IPv4 Address: 195 51 100.14
Unique Identifiers: 4,294,967,290

Example IPv6 Address: 2001:D88:BE:C001:1234:ABCD:22:1
Unique Identifiers: 340,282,366,920,938,463,374,607,431,768,211,456

6. IPv5 Anyone?
If you're wondering what happened to IPv5, also called the Internet Stream Protocol, it was developed in the 1980s as an experiment. It was created to transmit audio, video and simulations over the Internet. It was never used as an official protocol. In its original form, IPv5 was never widely distributed. It was, however, adapted and developed into what's now known as ST2.

7. Negative Impact
Not deploying IPv6 will negatively impact you, sooner or later. A lack of Internet addresses means that networks are coping by trying to reuse existing addresses among more customers, which can disrupt some of your favorite Internet applications, so services that allow for incoming connections, such as gaming, will become difficult to use. Similarly, as more of the world is connected directly by IPv6, they won't connect directly to your Website or applications and services unless they are offered over IPv6.

8. The Time Is Now
The time to deploy IPv6 is now. For network operators and other entities relying on Internet numbering allocations, it will become increasingly difficult and expensive to obtain new IPv4 address space. The cost and complexity associated with keeping track of and managing remaining IPv4 address space efficiently will also increase. To ensure long-term network growth and global connectivity, network operators and enterprises need to implement IPv6.

9. IPv6 Is the Future
IPv6 is the future. An enormous amount of IP address space exists under IPv6. IPv6, in fact, was specifically designed to fix the address limitations of IPv4. This addressing capacity will enable more than 340 trillion, trillion, trillion addresses of new Internet addresses needed to support connectivity for a huge range of smart devices such as phones, household appliances and vehicles

10. June 6 launch
World IPv6 Launch: June 6. During this landmark event, organized by the Internet Society, major Websites, network access providers and home router vendors are permanently enabling IPv6 as part of their regular business operations. This marks the beginning of a new phase in the life of the Internet, when IPv6 begins to become a normal part of the Internet experience for everyone. Join the launch here.

(The link provided at "Join the launch here" in the last line apparently isn't online yet.)


Anyone who's waded through down to here is authorized to print their own "Hero Button" or whatever other reward is deemed suitable.

John