Rapid exploration of Internet live address space using optimal discovery path

Several Internet mapping and topology discovery applications inspect multiple IP (Internet protocol) addresses to discover Internet address regions that are alive, i.e., contain IP addresses that elicit replies to probes. Currently, the traditional approach in examining these IP addresses is completely random, uses exhaustive scan, or focuses on a common wisdom of checking the first IP in each address region. In this paper, we first formalize the discovery process, then we provide an efficient solution to the problem of declaring an address prefix (AP) alive by discovering a reachable host within its addressable range. We develop and evaluate an optimal discovery path that prioritizes and orders probes to a small subset of IP addresses within each AP. Using our optimal discovery path technique, we show that examining a maximum of 11 different IP addresses within each AP successfully reveals the aliveness of more than 90% of the APs.