On IPv4 transfer markets: Analyzing reported transfers and inferring transfers in the wild
IPv4 Transfer Markets have recently emerged as a mechanism for prolonging the usability of IPv4 address space. They facilitate the trading of IPv4 address space, which constitutes a radical shift transforming IPv4 addresses from a free resource to a commodity. In this paper, we conduct a comprehensive analysis of all IPv4 transfers that are published by three regional Internet registries. We analyze the overall evolution of transfer markets, whether they lead to a healthy redistribution of IP addresses, and the interplay between transfers and IPv6 adoption. We find that, to a large extent, IPv4 transfers serve their intended purpose by moving IP blocks from those with excess to those in need - transferred address blocks appear to be routed after the transfer, the utilization of transferred blocks is greater after the transfer date and a high percentage of the transferred space comes from legacy space. We have also proposed a methodology for detecting IPv4 transfers in the wild that tracks changes in origins of IP prefixes in the global routing table. This method yields promising results, yet it produces a large number of false positives due to the noisy nature of routing data. We have investigated the cause of these false positives and verified that they can be reduced to a volume analyzable by a human operator.