Patent ID: 7554924

Claim:
For use with a subnet having a channel adapter and a switch in which the channel adapter and the switch each have a plurality of ports and in which each channel adapter port is intended to have a globally unique identifier and is intended to be connected to a respective one of the switch ports, a method of checking for whether two or more channel adapter ports have the same globally unique identifier during a discovery of the subnet, the method comprising: for each channel adapter port, storing, by a subnet manager in communication over the subnet with the channel adapter and the switch, the globally unique identifier of the channel adapter port, data indicative of a generation count of discovery for the channel adapter port, data identifying the switch port that the channel adapter port is intended to be connected at an initial time, wherein the switch port that the channel adapter port is intended to be connected at the initial time is an original peer of the channel adapter port, and data indicative of a generation count of discovery for the original peer of the channel adapter port; selecting at a given time subsequent to the initial time, by the subnet manager, one of the channel adapter ports, wherein the selected channel adapter port is connected at the subsequent time to a given one of the switch ports such that the given switch port is a current peer of the selected channel adapter port; determining, by the subnet manager, if there is a change between the current and original peers of the selected channel adapter port; and determining, by the subnet manager, that there is no duplication of the globally unique identifier of the selected channel adapter port with the globally unique identifier of any other channel adapter port if the current and original peers of the selected channel adapter port are the same.