OSPF is designed for scalability, so some LSAs are not flooded out on all interfaces, but only on those that belong to the appropriate area.
Inter-Area-Prefix-LSAs (OSPFv3) Inter-Area-Router-LSAs (OSPFv3) At the area border router, selected type-7 LSAs are translated into type 5-LSAs and flooded into the backbone.
For example, OSPF-TE has traffic engineering extensions to be used by RSVP-TE in Multiprotocol Label Switching (MPLS).
Standard link-state database (LSDB) flooding mechanisms are used for distribution of opaque LSAs.
for LSA only packet that matches the destination routes willingness is forward.
Communicating a large LSDB may require several messages to be sent by having the sending device designated as a master device and sending messages in sequence, with the slave (recipient of the LSDB information) responding with acknowledgments.
They are sent in response to a link state request message, and also broadcast or multicast by routers on a regular basis.