Patent ID: 8018876

Claim:
A method for managing routing in an IP network arranged for OSPF routing with an area zero including core routers and hub routers, comprising for each node linked to a core router, establishing at least two separate hierarchical levels of node signatures; assigning one of the at least two node signatures to each node based on whether the node is one of the core routers or one of the hub routers; assigning link signatures based on node signatures; requiring certain link signatures for routing certain internode traffic by: identifying node types of the certain internode traffic; identifying links with types which match the node types, the identifying of links resulting in a set of identified links and non-identified links; and designating the identified links as available and the non-identified links as unavailable; running OSPF routing algorithms for separate origin-destination network segments, the separate origin-destination network segments handling core to core traffic, hub to core traffic, and hub to hub traffic, based on the designated available node and certain link signatures to return OSPF routing for the separate origin-destination network segments; and routing traffic over the IP network based on such OSPF routing, whereby the traffic will not be routed over links not designated as available during conditions of IP network breakdown.