In February I commented about how we have been doing some research into the use of unallocated address space on the Internet. I hoped that I could give a report on the results sooner than this but the work has now been done and the results have been made public.
Duane Wessels of The Measurement Factory analysed DNS queries for evidence of how unallocated IPv4 addresses are being used and presented them at the last OARC meeting, last month. The results cannot give a complete view of what is happening, as it does not see what is happening in private, behind closed firewalls. Nonetheless, these are useful data.
We will be using these data to help plan for the last few IPv4 allocations to the RIRs.