  We investigate efficient methods for packets to navigate in complex networks.
The packets are assumed to have memory, but no previous knowledge of the graph.
We assume the graph to be indexed, i.e. every vertex is associated with a
number (accessible to the packets) between one and the size of the graph. We
test different schemes to assign indices and utilize them in packet navigation.
Four different network models with very different topological characteristics
are used for testing the schemes. We find that one scheme outperform the
others, and has an efficiency close to the theoretical optimum. We discuss the
use of indexed-graph navigation in peer-to-peer networking and other
distributed information systems.
