Patent ID: 6980524

Claim:
In a network having a plurality of nodes arranged in at least two zones, a method for a particular node to determine a current partial topological state of the network, the method comprising: a) determining a zone of the network in which the particular node resides; b) for each node in the zone, determining nodes having a physical communication link with the node in the zone; and c) for each zone in the network, determining zones having a virtual connection with the zone in the network, wherein the act of determining nodes having a physical communication link with the node in the zone includes: i) broadcasting a link request from the node; ii) if a response to the link request is received by the node, A) if the response was from a node within the same zone as the node, storing an identifier of the responding node, and B) if the response was from a node that is not within the same zone as the node, storing an identifier of the zone to which the responding node belongs; and iii) broadcasting, from the particular node, a link state message including the identifier of the responding node if the response was from a node within the same zone and the identifier of the zone to which the responding node belongs if the response was from a node not within the same zone as the node.