In a paper to be presented later this month at the Proceedings of the ACM Internet Measurement Conference, a team of six researchers have documented what they claim is the first complete census of the Internet in more than two decades. They discovered a surprising number of unused addresses and conclude that plenty will still be lying idle when the last numbers are handed out in a few years' time. The problem, they say, is that some companies and institutions are using just a small fraction of the many million addresses they have been allocated.
"People are very concerned that the IPv4 address space is very close to being exhausted," says John Heidemann, a research associate professor in the department of computer science at the University of Southern California (USC) and the paper's lead author. "Our data suggests that maybe there are better things we should be doing in managing the IPv4 address space."
