Patent ID: 8644313

Claim:
A method of operating a link state protocol controlled network comprising a plurality of nodes having respective topology databases for storing a representation of a topology of the network, the method comprising: detecting a network topology change; computing, in at least one node, respective information characterizing shortest unicast paths from the at least one node to at least one other node; detecting, in at least one node, whether an “unsafe” condition exists; at nodes where an “unsafe” condition is detected, removing forwarding state for multicast paths originating at other network nodes and subsequently advertising a “safe” indication to each neighbour node of the advertising node, the “safe” indication comprising a digest of the topology database of the advertising node; installing, in respective filtering databases (FDBs) at nodes achieving a “go” condition, forwarding state associated with multicast paths, the “go” condition comprising receiving at least one respective “safe” indication from at least one neighbour node; and forwarding packets in at least one node achieving a “go” condition based on the installed forwarding state.