In this paper we discuss requirements for peer-to-peer (P2P) benchmarking, and we present two exemplary approaches to benchmarks for Distributed Hashtables (DHT) and P2P gaming overlays. We point out the characteristics of benchmarks for P2P systems, focusing on the challenges compared to conventional benchmarks. The two benchmarks for very different types of P2P systems are designed applying a common methodology. This includes the definition of the system under test (SUT) and particularly its interfaces, the workloads and metrics. A set of common P2P quality metrics helps to achieve a comprehensive selection of workloads and metrics for each scenario.