Patent ID: 6934263
Filing Date: 2005-08-23
Classification: H04L

Abstract:
1. For a network comprising a plurality of network segments, a network device comprising: a plurality of ports coupled to segments in the network; and topology management resources which manage the plurality of ports according to a spanning tree algorithm, to set an active topology for the plurality of ports; including memory storing parameters for specifying the active topology, the parameters including information for an identification of a root of the network, identification of a port in the plurality of ports for a root port role to be used for a path to the root, identification of one or more ports in the plurality of ports for designated port roles to be used for paths between the root and respective segments coupled to the one or more ports, and identification of one or more ports in the plurality of ports for alternate port roles; logic to compute states for ports in the plurality of ports in response to the parameters, including placing the port in the root port role in a forwarding state, placing the one or more ports in the designated port roles in a forwarding state, and placing the one or more ports in the alternate port roles in a blocking state; and logic to manage transition of the states of the ports in the plurality of ports in response to a change in the active topology, including for a port changing to a designated port role, issuing a message informing a recipient that the port is able to change to a forwarding state, and then upon receipt of a ready signal from the recipient, causing a transition to the forwarding state.