Abstract: In a computer system that includes multiple physical enclosures, an enclosure includes a non-volatile memory that includes bus numbering information for its own buses as well as bus numbering information for one or more of its neighbors. In the preferred implementation, all enclosures include a non-volatile memory that includes bus numbering information for its own buses and for both of its neighbors. This creates a distributed database of the interconnection topology for the computer system. Because an enclosure contains bus numbering information about its neighbor enclosure(s), the bus numbers for the buses in the physical enclosures are made persistent across numerous different system reconfigurations. The preferred embodiments also include a bus number manager that reads the non-volatile memories in the physical enclosures during initial program load (i.e.