Patent ID: 7042850
Filing Date: 2006-05-09
Classification: H04L

Abstract:
1. A method of propagating link state information in a routing area of a network including a plurality of routers, comprising: generating a node state advertisement at a first router of the plurality of routers, the node state advertisement identifying the first router and a link about which the first router desires to receive link state information; flooding the node state advertisement throughout the routing area so as to ensure that substantially all of the plurality of routers receive the node state advertisement; at each of the routers receiving the node state advertisement, determining whether the receiving router lies along a path meeting a predetermined criteria between the link and the first router; and at each of at least one second router determined to lie along such a path, (1) maintaining an association between the link and the first router, the association indicating that link state advertisements concerning the link are to be forwarded along the path toward the first router, and (2) upon a change of the state of the link, forwarding a corresponding link state advertisement to an adjacent one of the routers along the path toward the first router.