Scraping the Bottom of the Barrel

By Sean Hopkins - Policy Analyst, ARIN

We’ve been yelling to the rafters for a couple of years now about how we’re running out of IPv4 address space. We hope you heard us and that you’re preparing for it with IPv6. But what we haven’t explained up until now is the full progression in the march toward Total IPv4 Exhaustion. Check out our nifty new fact sheet that explains it all.

Here are the basics:

First, there’s the IANA free pool. This is where all five RIRs get our address space, in big chunks called /8s. There are 256 of those in the whole IPv4 pool; a few are unavailable for things like multicast and experimental networks, and the rest either already have or soon will go to the RIRs. Right now, there are seven of them left. That’s 2.73% of the total. Factor in the global policy that says the last five /8s in the IANA free pool go one each to the five RIRs, and really that means that there are two left. We expect those to be distributed to the RIRs in early 2011.

At that point, unless there is a change to global policy, the RIRs won’t be able to get any more IPv4 address space from IANA. We’ll each have one full /8, plus whatever inventory we had on hand on Depletion Day. We’ll distribute that address space according to our existing policies for as long as possible. Depending on demand, this could last anywhere from a few days to several months.

What we know for sure is that eventually we’re going to have to start denying requests that we can approve today, simply because we won’t have enough space. While we will have some small pockets of IPv4 available here and there with the natural cycle of returned, revoked, and reclaimed address space, we won’t have the larger blocks of IPv4 addresses that you need.

Once our inventory is down to those last small pieces, the only IPv4 address space left will be in the local pools: the ISPs. They’ll hand out space for as long as possible too, and again demand will dictate how long it’ll last.

Of course the Internet will not come to a grinding halt the day the IANA pool hits zero. Instead, it’ll be a gradual shift from the IANA free pool, to the RIR free pool, to the ISP free pool, to the You Better Have IPv6 By Now Or You’re In Trouble days.

Want to get ahead of the curve? Deploy IPv6 today. We’ve got PLENTY of that resource and are happy to distribute it. Check out the IPv6 Wiki if you want more technical information, or poke around the Education section here for more links. Need to convince your management this is the real deal? We’ve got a management-friendly community use slide deck to present, complete with detailed speaker notes. Want us to come explain it at a local conference? Let us know.

We’re here to help. The Registration Services Help Desk is open from 7AM to 7PM ET for your Internet number resourcing needs. Get started today!

POST WRITTEN BY:

Sean Hopkins

Policy Analyst, ARIN