Abstract: Communication network routing apparatus and techniques using logical communication links are disclosed. A routing apparatus identifies a logical communication link that it is capable of being used to establish a virtual connection with another routing apparatus within a virtual connection operational domain, which includes multiple sub-domains, of an underlying communication system. A destination that is associated with the routing apparatus and is reachable through the virtual connection is also identified. Information that is indicative of the identified logical communication link and of the identified destination is provided for distribution from a sub-domain of the routing apparatus in the virtual connection operational domain to another sub-domain within the virtual connection operational domain. This distribution of information enables a routing apparatus in one sub-domain to dynamically route a virtual connection toward a destination in a different sub-domain.

Abstract: A router executes a flooding algorithm. The router maintains a list of neighbors within an area data structure. When a new neighbor arises on an interface belonging to an area served by the router, the router updates the neighbor data structure describing that adjacency by linking it to a corresponding entry in the list of neighbors. Utilizing information contained in the list of neighbors, as well as information describing the types of interfaces used by the neighbors in the list, the router marks each interface data structure within the area as either flooding-active or flooding-passive. Marking of the interface is performed in connection with an interface election process that selects a flooding-active interface on the basis of, e.g., interface cost, giving preference to faster interfaces. Thereafter, link state protocol data units (PDUs) are sent to the neighbors over those interfaces marked as flooding-active.