The year in IPv4 addresses: almost 200 million served

One of the first things I do every year on the first of January is have a look at what happened with the IP address stockpile during the previous year. We started 2008 with 1,122.85 million unused addresses left and we ended it with 925.58 million. So the world used up 197.27 million IPv4 addresses in 2008, increasing use of the total address space from 69.7 percent a year ago to 75.3 percent now.

The IP address space is managed by the Internet Assigned Numbers Authority (IANA), which is part of ICANN, the people who normally debate the virtues of .xxx domains. IANA maintains a list of 256 blocks of 16,777,216 IPv4 addresses each, identified by the first 8-bit number in an IP address. Each of those "/8" blocks is either delegated to a Regional Internet Registry (RIR), is unallocated (available for future delegation), has legacy status, or is reserved for a special use.

The table below shows the overall distribution of IPv4 addresses among the regional registrars.

APNIC (Asia-pacific region) and ARIN (North America) both got four new /8 blocks last year—ARIN got two of those just before Christmas. LACNIC (Latin America and Caribbean) and especially AfriNIC (Africa) still have a lot of address space to work with, but it looks like the RIPE NCC (Europe, Middle East, former USSR) will be receiving more address space from IANA soon.

The block that was added to the legacy pile is 7.0.0.0/8, which was given out to the US DoD Network Information Center, which apparently didn't want this information to appear in the IANA list, but it's now listed as "administered by ARIN." (See my full report for additional caveats.)

Things get more interesting when we look at the top 15 list of largest IP address-using countries. The US is still at the top, having 52.4 percent of all IPv4 addresses in use—which includes the vast majority of the legacy space. However, a few years ago this was at 60 percent, so 52 is actually an improvement.

Despite that, the US was still the largest user of new IPv4 addresses in 2008 with 50.08 million addresses used. China was a close second with 46.5 million new addresses last year, an increase of 34 percent.

Although China and Brazil saw huge increases in their address use, suggesting that the developing world is demanding a bigger part of the pie while IPv4 addresses last, what's really going on is more complex. India is still stuck in 18th place between the Netherlands and Sweden at 18.06 million addresses—only a tenth of what China has. And Canada, the UK, and France saw little or no increase in their numbers of addresses, while similar countries like Germany, Korea, and Italy saw double-digit percentage increases.

A possible explanation could be that the big player(s) in some countries are executing a "run on the bank" and trying to get IPv4 addresses while the getting is good, while those in other countries are working on more NAT (Network Address Translation) and other address conservation techniques in anticipation of the depletion of the IPv4 address reserves a few years from now.

In both cases, adding some IPv6 to the mix would be helpful. Even though last year the number of IPv6 addresses given out increased by almost a factor eight over 2007, the total amount of IPv6 address space in use is just 0.027 percent.