We have been collecting and recording routing paths from a test host to each of over 90,000 registered networks on the Internet since August 1998. The resulting database contains interesting routing and reachability information, and is available to the public for research purposes. The daily scans cover approximately a tenth of the networks on the Internet, with a full scan run roughly once a month. We have also been collecting Lucent's intranet data, and applied these tools to understanding its size and connectivity. We have also detected the loss of power to routers in Yugoslavia as the result of NATO bombing.
A simulated spring-force algorithm lays out the graphs that results from these databases. This algorithm is well known, but has never been applied to such a large problem. The Internet graph, with around 88,000 nodes and 100,000 edges, is larger than those previously considered tractable by the data visualization community. The resulting Internet layouts are pleasant, though rather cluttered. On smaller networks, like Lucent's intranet, the layouts present the data in a useful way. For the Internet data, we have also tried plotting a minimum distance spanning tree; by throwing away edges, the remaining graph can be made more accessible.
Once a layout is chosen, it can be colored in various ways to show network-relevant data, such as IP address, domain information, location, ISPs, and result of scan (completed, filtered, loop, etc).
This paper expands and updates the description of the project given in an IEEE Computer article [1].