Patent ID: 7701881

Claim:
A method for reducing spanning tree instances in a network, the method comprising: receiving in an instance merger of a network device on the network, first and second spanning tree instances corresponding to a portion of the network, the network having a plurality of participating stations; determining an optimal root for each of the first and second spanning tree instances; accessing configuration information from each of the first and second spanning tree instances, wherein the configuration information comprises a forwarding port, a blocked port, and the optimal root; comparing the configuration information accessed from the first and second spanning tree instances to determine whether the first and second spanning tree instances are merge-able, the merge-able determination implementing a subtree reduction comprising: determining if at least one of a forwarding port set and a blocking port set of each of the first and second spanning tree instances are substantially equivalent; determining if one of the first and second spanning tree instances is a superset of remaining spanning tree instances; and determining, if at least one of a forwarding port set and a blocking port set of each of the first and second spanning tree instances are substantially equivalent and if one of the first and second spanning tree instances is a superset of remaining spanning tree instances, that the first and second spanning tree instances are conditionally merge-able; merging the first and second spanning tree instances into a merged topology instance when the merge-able determination indicates that the first and second spanning tree instances are merge-able; and deploying one or more merge indicators to the plurality of participating stations to indicate that the first and second spanning tree instances have been merged into the merged topology instance, the one or more merge indicators being used by the participating stations to perform a corresponding merging of the first and second spanning tree instances.