Abstract: In a distributed computer system having multiple root nodes, a challenge protocol is provided, for use in determining or confirming the root node in which a PCI Configuration Manager (PCM) actually resides. This node is referred to as the master node. The challenge procedure is activated whenever the identity of the PCM, which is determined by the root node in which it resides, appears to be uncertain. The challenge procedure resolves this uncertainty, and enables the PCM to continue to configure routings throughout the system. In a useful embodiment, a method is directed to a distributed computer system of the above type which is further provided with PCI switches and with adapters that are available for sharing by different nodes. The method includes the steps of selecting a first one of the root nodes to be master root node, and operating the first root node to query the configuration space of a particular one of the PCI switches.