Abstract: From a computational point of view, switchbox routing problem is considered to be a hard combinatorial problem. Traditional algorithmic method is not suitable for solving this problem, since it leads to "combinatorial explosion" in search space. The effective method to solve the problem would be expert system. In this paper, a prototype of a rule-based expert system for two-layer switchbox routing is introduced. The design of inference engine and the organization of knowledge base are the two features of the expert system.