A computer-implemented method for simulating a system of at least two computing systems connected via at least one data packet connection, wherein a computing system comprises interconnect adapters for physical connections based on a physical layer protocol each. A packet switching component is provided, as are physical attachments for each interconnect adapter. The physical attachments are registered. A connection director is provided for managing the data packet exchange. In response to the receipt of a simulation start indicator, each physical attachment registers its unique address at the package switching component. This assigns unique identifiers for each computing system, and unique identifiers for simulated physical layer protocols.