Census and Survey of the Visible Internet

Prior measurement studies of the Internet have explored traffic and topology, but have largely ignored edge hosts. While the number of Internet hosts is very large, and many are hidden behind firewalls or in private address space, there is much to be learned from examining the population of visible hosts, those with public unicast addresses that respond to messages. In this paper, the authors introduce two new approaches to explore the visible Internet. Applying statistical population sampling, they use censuses to walk the entire Internet address space, and surveys to probe frequently a fraction of that space.