USB Hub Devices

• Do not cascade hubs beyond four levels on either SPARC or IA systems. On SPARC systems, the Open Boot PROM (OBP) cannot reliably probe beyond four levels of devices.

• Do not cascade bus-powered hubs. This means you cannot plug a bus-powered hub into another bus-powered hub. A bus-powered hub does not have its own power supply. A USB diskette device derives all its power from the bus and might not work on a bus-powered hub.