The IPv4 Census Maps use data from the LANDER project at USC/ISI. They make periodic Internet-wide surveys by sending ICMP ``pings'' to every IPv4 address, except those not yet allocated by IANA.
Colors in the image represent the number of hosts that responded to the pings. Some hosts do not respond to the probes due to firewalls, NAT boxes, and ICMP filtering. Thus, the data and map give us a lower bound on IPv4 address utilization.
Here we have maps showing the results of their numerous surveys, going back to mid-2003. Each image is 4096x4096 pixels, and about 5 MB.
Information Sciences Institute at the University of Southern California. Internet Addresses Survey dataset, DHS PREDICT ID USC-LANDER/internet_address_survey_it15w-20061108. Traces taken 2006-11-08 to 2007-01-08. Provided by the USC/LANDER project. http://www.isi.edu/ant/lander/.
© 2009 The Measurement Factory.