My book: 'Running IPv6' by Iljitsch van Beijnum BGPexpert My book: 'BGP' by Iljitsch van Beijnum

Home · BGP Expert Test · What is BGP? · BGP Vendors · Links · Archives · Books · My BGP Book

2014 in IPv4 addresses: closing the books on IPv4

Ten years ago, I published my first "IPv4 address use report" over 2005. After that, I did 2006, 2007, 2008, 2009, and 2010. Today, I'm going back to the well one last time and provide an overview of what happened with the IPv4 addresses the past decade, which will close the book on the IPv4 address space as far as I'm concerned.

At the end of 2005, 2056.30 million of the 3706.65 usable IPv4 addresses had been given out: 55%. Today, it's 3592.99 million, which is 97%. Can you imagine driving a car with a tank filled to 3%? Or work on a computer with a drive that's 97% full?

All the numbers I present here are based on those published on the FTP servers of the five Regional Internet Registries that give out IP addresses. So an address is "in use" if an RIR has given it to an ISP or directly to an end-user organization. Whether that ISP or that organization actually uses the address is something we can't tell from these numbers.

Let me first explain the 3706.65 million number. IP addresses are 32 bits long, which means there's 2³² = 4,294,967,296 of them: 0.0.0.0 to 255.255.255.255, or 256 blocks of 16,777,216 addresses that start with the same number. We call one of those a "/8" in the business. 0/8 (or 0.0.0.0/8, which is 0.0.0.0 - 0.255.255.255) and 127/8 can't be used because they each contain one special address. 224/4 (everything starting with 224 to 239) is used for multicast and 224/4 (240 - 255) is "reserved for future use". This prompted some programmers who are a bit too fond of input validation to reject those addresses. As a result, those addresses can't be used on many systems, some of which are no longer updated, but still used. So 268 million perfectly good IPv4 addresses will probably remain unused forever. Last but not least, there's the 17,891,328 addresses set aside for private use: 10/8,172.16/12 and 192.168/16. So the total usable IPv4 address space is 222 × 16,777,216 - 17,891,328 = 3,706,650,624.

By downloading the old address delegation records from the RIR FTP servers it's possible to see how many addresses were given out at the end of each year. (Looking at just the latest files gives different results because addresses that have been returned in the meantime aren't listed in those.) This is the number of IPv4 addresses given out as of the end of the last ten years:

This is the net difference between each year and the previous year:

In this graph, the year 2014 looks strange, as two old class A blocks (16.78 million addresses each) that are used in Europe now fall under the RIPE NCC, while they were previously listed in the ARIN statistics. If we exclude all the "legacy" /8 blocks, the trend makes more sense:

(However, now there's a spike in 2012 for ARIN as a few of these blocks changed their status.)

APNIC and the RIPE NCC have been running on fumes for the past several years: ISPs in their region can only get one last block of 1024 addresses after those two dipped below the 16.78 million address mark (a /8 block). This happened in 2011 for APNIC and in 2012 for the RIPE NCC. This year, ARIN and LACNIC also reached a similar status, although ARIN doesn't use the "one last block" policy.

As a result, organizations that need IPv4 addresses now have to buy them from others who can spare some. IPv4 address transfers were especially big in the RIPE region in 2014. In the ARIN region, the number of transfers was limited at 180 in five years, but the size of the blocks transferred tended to be large; apparently here transfers were mainly used to get larger amounts of address space than what could (then still) be obtained directly from ARIN. Inter-RIR transfers are now also possible, and happen exclusively from the ARIN region to the APNIC region. See the RIPE and ARIN transfer statistics on their websites and APNIC's on their FTP server.

This is how three kinds of numbers compare: the addresses given out with a datestamp of 2014, the net difference between the total number of IPv4 addresses given out, and the number of addresses transferred in 2014:

                   AfriNIC APNIC   ARIN    LACNIC  RIPE NCC
 
Given out 2014:    12.45    3.77   26.06   19.11    2.61
 
Intra-RIR
transfers 2014:             3.85    2.98            9.61
 
Inter-RIR
transfers 2014:             1.10   -1.10
 
Net difference
2014-01-01 -       12.72    4.62   18.82   18.74    0.27
2015-01-01:    

When I compiled my first statistics over 2005, this was the list of the 15 biggest IPv4 address users:

Country   Addresses
 
US      1324.93 M        United States
JP       143.00 M        Japan
EU       113.87 M        Multi-country in Europe
CN        74.39 M        China
CA        67.43 M        Canada
DE        51.13 M        Germany
FR        45.16 M        France
KR        41.91 M        Korea
UK        40.18 M        United Kingdom
GB        33.63 M        Great Britain
AU        26.87 M        Australia
IT        18.39 M        Italy
BR        17.17 M        Brazil
NL        16.40 M        Netherlands
ES        16.29 M        Spain

Nine years later, the list looks like this:

Country   Addresses
 
US       1596.02 M        United States
CN        331.99 M        China
JP        202.61 M        Japan
GB        123.75 M        United Kingdom
DE        118.91 M        Germany
KR        112.32 M        South Korea
FR         84.05 M        France
BR         81.02 M        Brazil
CA         80.41 M        Canada
IT         53.44 M        Italy
AU         48.48 M        Australia                         
NL         45.94 M        Netherlands
RU         45.55 M        Russian Federation                
IN         36.36 M        India
TW         35.47 M        Taiwan

Surprisingly little has changed, although the BRIC countries have claimed a bigger piece of the pie. I don't know why India has barely a tenth of the number of IPv4 addresses that China has.

So long IPv4, it's been good knowing you.

Comments or questions? Email me.