Computer Science Department
School of Computer Science, Carnegie Mellon University
Measuring an IP Network in situ
This thesis explores ways to measure five different aspects of the Internet. The first aspect considered is the Internet's topology, the inter-connectivity of the Internet. This is one of the basic questions about the Internet: what hosts are on the Internet and how are they connected? The second aspect is routing: what are the routing decisions made by routers for a particular destination? The third aspect is locating the source of a denial-of-service (DoS) attack. DoS attacks are problematic to locate because their source is not listed in the packets. Thus, special techniques are required. The fourth aspect is link delays. This includes both a general system to determine link delays from end-to-end measurements and a specific system to perform end-to-end measurements from a single measurement host. The fifth aspect is the behavior of filtering on the network. Starting about fifteen years ago, to increase security, corporations started placing filtering devices, i.e., "firewalls", between their corporate network and the rest of the Internet. For each aspect, a measurement system is described and analyzed, and results from the Internet are presented.