@misc{10325, keywords = {Conference}, author = {Ioana Livadariu and Ahmed Elmokashfi and Amogh Dhamdhere and Kc Claffy}, title = {A First Look at IPv4 Transfer Markets}, abstract = {In February 2011 the Internet Assigned Numbers Authority (IANA) exhausted its free pool of IPv4 addresses, and the regional registries (RIRs) have started to run out of IPv4 addresses as well. As RIRs have started rationing allocations, IPv4 transfer markets have emerged as a new mechanism to acquire IPv4 addresses. Barring a few high-profile exceptions, IPv4 transfers have largely flown under the radar. In this work, we use the lists of transfers published by three RIRs to characterize the transfer market - the types of players involved, the sizes and characteristics of transferred address blocks, and visible effects on the routing table. Next, we take first steps toward detecting address transfers using BGP data from the Routeviews and RIPE repositories from 2004-2013. We identify reasons why legitimate changes in prefix origin could be confused as transfers, and implement a series of 10 filters that remove 86\% of candidate transfers. We find the remaining number of inferred transfers is increasing over time. We could confirm few (0.16\%) of these transfers using RIR-published transfer lists; while our inference methodology undoubtedly yields false positives, a black market for IPv4 transfers may exist as well.}, year = {2013}, journal = {CoNEXT 2013}, pages = {7-12}, month = {December}, publisher = {ACM SIGCOMM}, isbn = {978-1-4503-2101-3}, editor = {Dina Papagiannaki and Vishal Misra}, }