OSPF Database Exchange Summary List Optimization
This document describes a backward compatible optimization for the Database Exchange process in OSPFv2 and OSPFv3. In this optimization, a router does not list an LSA in Database Description packets sent to a neighbor, if the same or a more recent instance of the LSA was listed in a Database Description packet already received from the neighbor. This optimization reduces Database Description overhead by about 50% in large networks. This optimization does not affect synchronization, since it only omits unnecessary information from Database Description packets.