Patent ID: 6628624
Filing Date: 2003-09-30
Classification: H04L

Abstract:
An intermediate network device for use in forwarding messages in a computer network, the device having a plurality of ports for connecting the device to one or more network components, at least one port configured such that messages forwarded for transmission from the at least one port are also looped-back to the device, the intermediate network device comprising:an enhanced spanning tree entity configured to formulate at least one configuration bridge protocol data unit (BPDU) message for transmission from one or more ports, the enhanced spanning tree entity further configured to examine the contents of one or more BPDU messages received at the ports; a spanning tree memory coupled to the enhanced spanning tree entity for storing a loop-back detection data structure comprising one or more BPDU data elements from the at least one transmitted BPDU message; and a comparator for comparing BPDU data elements of the loop-back detection data structure with corresponding fields of the one or more received BPDU messages; and a spanning tree state machine engine for placing a first port in a blocking state, in response to a determination as made by the comparator that one or more BPDU messages received at the first port is the same as the corresponding loop-back detection data structure.