Packet Guide to Core Network Protocols

Chapter . Internet Protocol Version 6

This proliferation of class C network numbers may aid in preserving the scarcity of class A and B numbers, but it is sure to accelerate the explosion of routing information carried by Internet routers.

These recommendations for management of the current IP network number space only profess to delay depletion of the IP address space, not to postpone it indefinitely.

—RFC 1366

As we have already discussed, the language of the World Wide Web is the Internet Protocol (IP) or more specifically, IP Version 4. But for a long time folks have been talking about the demise of IPv4, primarily due to IP address space exhaustion. This means that eventually there would not be any more addresses that could be assigned, begged, borrowed or stolen for the public address space. So, an idea was born that would solve that problem and add additional features to the system. The year 1995 saw the publication of RFC 1752, which summarized the concerns and research for the previous five years—namely, that the IPv4 address space would not last forever. It had been predicted that the world would reach IP address exhaustion sometime between 2005 and 2011. While this prediction was not embraced by everyone, it cannot be denied that in February 2011, the Number Resource Organization (NRO) announced that:

As of 3 February 2011, the central pool of available IPv4 addresses managed by the Internet Assigned Numbers Authority (IANA) has been depleted.

The NRO states that for the foreseeable ...