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What is a good IPv4 block size to sell?

Published on April 29th, 2019

Potential Sellers of IPv4 resources often ask questions such

  • What is the most common size of IPv4 block sold?
  • Should I sell a /20 or a /19? Which will sell faster?

At IPv4 Market Group, we experience demand for block sizes that mirror the overall market.  John Sweeting, ARIN’s Senior Director for Registration Services, presented the chart shown in Figure One at the ARIN 43 meeting (April 2019).

Figure One:  2108 In-Region ARIN transfers by Block Size
Figure One:  2108 In-Region ARIN transfers by Block Size

As John shows, as illustrated by the general slope from left to right, there is more demand for smaller blocks.  But there is an interesting bump at the /16 size, where five times as many /16s sell as /17s.  Given that all block sizes (except /11s) are represented, we can see any IPv4 block is a good size.

Which block sizes represent most of the market?  We thought it would be interesting to look at the number of IPs transferred within each block size.  We looked at this in two stages.  Referencing Figure Two we first examined /24s to /17s.

Figure Two:  /24 to /17 - Number of IPs Transferred in ARIN in 2018

The general growth in the number of IPs transferred from left to right shows that the larger blocks account for most IPs transferred within the small block range.  The anomaly is /17s, where only 22 transfers occurred representing a total of 720K IPs transferred. 

In Figure Three we considered larger blocks of size /16 to /10 as a separate population, so that the scales of the smaller blocks did not become undetectable.

Figure Three: /16 to /10 - Number of IPs Transferred in ARIN in 2018

There is no clear pattern within the larger blocks, other than to note that 4 x /10 transfers dwarf the total IPs transferred in other sizes.  We can also see that /16s are the sweet spot compared to /15s to /11s.

From a supply versus demand point of view, if you have a question concerning what block sizes are in highest demand, then these charts point to our anecdotal experience:  It is best to create /20s, /19s and /16s as they are the most saleable block sizes.