The Internet is a network of competing networks.
Independent network operators have access to the proprietary
details of their own networks, but neither researchers nor
network operators have had access to the detailed, global
picture of the Internet needed to find and correct network
vulnerabilities and evaluate new applications and protocols.
My thesis work demonstrates that detailed topological and
routing information regarding the global Internet and its
constituent networks is within the reach of these
communities. That is, that reverse-engineering the Internet
can be made practical through innovative measurement
and inference techniques.
In this talk, I present my Rocketfuel system which
efficiently maps networks in the Internet using only
externally available information. To recover a reasonably
complete network graph, Rocketfuel uses hundreds of
traceroute servers as vantage points to collect paths
through the network. For efficiency, Rocketfuel uses global
routing information and prior measurements to guide further
measurement. To give the maps structure, Rocketfuel uses
the information encoded in router names to assign each
router to a geographic location and uses the rest of the
network graph to determine the role of each router in the
Topology is only part of the picture; the rules that govern
how packets are directed across the topology are equally
important but impossible to measure directly. I will
describe how routing can be inferred from paths not taken.
Inferred routing allows us to summarize and predict which
path a packet will traverse, as well as to find interesting
Understanding global Internet topology and routing allows
operators to predict the effects of change and allows
researchers to identify problems and demonstrate the
effectiveness of their solutions using realistic Internet