Patent ID: 8009591

Claim:
A method comprising: receiving on a first communication link at a local router all routing information at a certain level of detail for each router of a plurality of routers communicating in a first flooding domain; determining a measure of distance from a particular router in the first flooding domain to the local router; determining whether the measure of distance exceeds a threshold, wherein the distance reflects a number of hops between the local router and the particular router in the first flooding domain, wherein the distance is provided in a field of an update message exchanged between the local router and the particular router during a flooding event in the first flooding domain, and wherein the local router gives preference to a remote router that exceeds the threshold and for which the local router has the certain level of detail; and if it is determined that the measure of distance exceeds the threshold, then: determining summary routing information with less than the certain level of detail for the particular router, wherein the summary information includes an Internet protocol (IP) address for the particular router and a cost associated with reaching the particular router; and sending, over a different second communication link at the local router, routing information as open shortest path first (OSPF) link state advertisement (LSA) packets that include: the summary information for the particular router; and all routing information at the certain level of detail for a subset of routers communicating in the first flooding domain, wherein the subset excludes the particular router.