The current state of IPv4 is reminiscent of a great, old New Yorker cartoon. A doctor sits, peering at an X-ray. The patient is across the desk, looking anxious. The doctor says (more or less): "Well, Phil, after years of false alarms and hypochondria, we finally have something to work with."
For years, Internet insiders of all stripes have been warning that the supply of Internet addresses in the current scheme, IPv4, was going to run out. The worries grew even greater as mobility and machine-to-machine communications radically accelerated the rate of depletion.
But lots of people decided not to worry. To some extent, the run on the IPv4 bank was mitigated by clever workarounds. In the jargon of folks who want to say something is difficult without actually saying it is difficult, the changeover is "not trivial." IT departments also had a hard sell to management, since the concept of protecting against a rather geeky future threat is difficult, especially once the recession hit.
The bottom line is that the move to the next addressing scheme, IPv6, has been sluggish. While some progress has been made, time has run out. A variety of reports say that the depletion of IPv4 addresses could happen as soon as next week.
Computerworld had a very concisely written rundown of the final days of IPv4. The management structure of IP address awarding is fairly simple, considering the massive numbers and worldwide nature of the undertaking. The bottom line is that once a request level is reached, all the remaining blocks of addresses are automatically distributed to regional registries. Once those are gone, the only remaining IPv4 addresses are those from earlier blocks that for some reason weren't allocated.
The exhaustion of available IPv4 addresses from the IANA means that Internet Service Providers (ISPs) and Regional Internet Registries (RIRs) may be unable to fulfill requests for additional IPv4 address blocks from organizations with dwindling reserves of free addresses. IPv4-only organizations denied new addresses may face high capital expenditures to install and configure the networking equipment necessary to work around the lack of addresses.
The world now is split between organizations that have paid attention to the problem and are ready and those that have had not. Even at this late date, however, organizations can get to work. An AT&T press release, released today, offers six steps for IPv6 readiness. They are good suggestions. They are, however, long-term steps that won't be much of an immediate help to an organization that has dropped the ball to this point.
The more pressing matter-and what will become clear during the next several weeks-is how the industry will deal with the actual end of new IPv4 address availability. One thing that seems clear is that the opportunity for a smooth transition has passed.