— The design of a routing protocol must be based on the characteristics of its target networks. The diversity of wireless networks motivates the design of different routing metrics, capturing different aspects of wireless communications. The design of routing metrics, however, is not arbitrary since it has a great impact on the proper operation of routing protocols. Combining a wrong type of routing metrics with a routing protocol may result in routing loops and suboptimal paths. In this paper, we thoroughly study the relationship between routing metrics and routing protocols. Our work provides important guidelines for designing routing metrics and identifies the specific properties that a routing metric must have in order to be combined with certain type of routing protocols.