In 1995, on behalf of the IAB and IANA, I wrote a document called “Unique Addresses are Good” (RFC 1814). The Internet community had begun to worry about the depletion of the IPv4 address space at that time and the IAB and IANA started taking steps to slow the distribution of IPv4 addresses. One of those steps was to reserve certain addresses for private networks; networks whose numbers would never be seen or used by other networks. The premise was that the numbers could be reused by many private networks since those Internet numbers would never be visible outside of the private network. There was concern that by supporting the concept that an Internet address was no longer unique in the Internet system, chaos might ensue. The document explained the continuing benefits of using unique IP addresses and concluded by encouraging “any organization which anticipates having external connectivity [..] to apply for a globally unique IP address.”
The Internet has boomed in the intervening years and exceeded all our expectations. It now has a fundamental place in the economies of nations around the globe. The boom has gone so far that on February 3rd I allocated the last five blocks of IPv4 addresses from IANA’s central pool to the Regional Internet Registries (RIRs). The RIRs will allocate those IPv4 addresses to the networks in their regions in the coming months and maybe years.
The Internet uses IP addresses for its infrastructure, for the content we access and for the connections of ordinary Internet users. Recent studies indicate that approximately 2 billion people around the world have access to the Internet. And many of those 2 billion people may use 2 or more devices (computers, mobile phones, cable modems) that require an Internet address to deliver the service they want. The few billion addresses in IPv4 are barely enough for the services offered to 2 billion people much less for a world with a population of almost 7 billion.
There will be a period of transition and it will take time for the primary IPv4 infrastructure of the Internet to be replaced by IPv6 infrastructure. That transition will happen though because using the Internet has become an economic driver in all parts of the world.
I want to repeat the call I made in 1995 today because unique addresses are still good. And I urge everyone who anticipates building new Internet services, equipment and connections to provide support for globally unique IPv6 addresses. Having the wealth of unique addresses that IPv6 offers removes constraints that were placed upon innovation by the restricted availability of essential Internet addresses. IPv6 will enable the Internet’s future growth and there will be new opportunities for those already using the Internet as well as for those who will soon begin using it.