What is the secret of a fast-responding network? The ideal network will anticipate the communication needs of all nodes, building the necessary paths proactively. Unfortunately, this level of intelligence is not possible today. A brute-force approach, whereby the network continuously maintains all possible paths among all nodes, is also not a viable proposition because networks are far too vast and dynamic. This chapter explores strategies to reduce the impact of signaling in proactive routing. Through this exercise, we find that a fast network is one that can adaptively switch between "proactive" and "reactive" modes.