How can a network designer reduce the amount of LSA flooding occurring in a large, single area fully- meshed OSPF topology?

Passive interfaces suppress OSPF hellos entirely on that interface, preventing adjacency formation rather than controlling LSA flooding within an established topology.

ACLs cannot filter OSPF LSAs on a per-advertisement basis because OSPF uses multicast and the LSA database must be identical across all routers in an area to maintain convergence.

In a broadcast or non-broadcast multi-access network, the DR is responsible for flooding LSAs to all other routers using 224.0.0.5, while all others send updates only to the DR/BDR via 224.0.0.6. Placing the DR and BDR on the most central, high-capacity routers ensures the least redundant flooding paths and reduces overall LSA propagation overhead across the fully-meshed topology.

Moving point-to-point links into separate areas would reduce flooding through area segmentation, but this fundamentally changes the topology design rather than optimizing the existing single-area fully-meshed structure.