The need for semantic interoperability between ontologies in a peer-to-peer (P2P) environment is imperative. This is because, by definition participants in P2P environment are equal, autonomous and distributed. For example, the synthesis of concepts developed independently by different academic researchers, different research labs, various emergency service departments and, hospitals and pharmacies, just to mention a few, are an assertive request for cooperation and collaboration among these independent peers. In this work we are looking at issues that enable us to build a robust semantic consensus to solve the interoperability problem among heterogeneous ontologies in P2P networks. To achieve a robust semantic consensus we focus on three key issues: i. semantic mapping faults, ii. consensus construction iii. fault-tolerance. All these three issues will be further elaborated in this paper, initial steps to address theses issues will be described and fault-tolerant semantic mapping research directions will be further identified.