A method and apparatus is disclosed for determining interconnections of network devices. The network devices are connected together based on a set of general guidelines. A first network device is associated with a power state that is changed. Whether an alteration occurs at a second network device in response to the change in power state of the first network device is identified and stored. The changing of the power state of the first network device may be in response to a third network device and may be performed via a power controller. The alteration at the second network device may be a link becoming hot or the raising of a trap that is set at a switch. Errors are identified by comparing whether an alteration is identified to information in a database. Different types of interconnections may be determined in a series of phases by testing different types of devices.