OSPFv2 Link-state advertisement (LSA) types

OSPFv2 sends routing information in Link-State Advertisements (LSAs). The switches support the following types of LSAs.

Router LSA—Type-1 LSA. Describes the states of the router interfaces to an area, and is flooded throughout a single area only.
Network LSA—Type-2 LSA. Describes the list of routers connected to the network, and is flooded throughout a single area only.
Summary LSA—Type-3 LSA. Describes the route to networks in another OSPF area of the same Autonomous System (AS). Propagated through backbone area to other areas.
ASBR summary LSA—Type-4 LSA. Describes the route to an ASBR in an OSPF normal or backbone area of the same AS. Propagated through backbone area to other areas.
AS external LSA—Type-5 LSA. Describes the route to a destination in another AS (external route.) Originated by ASBR in normal or backbone areas of an AS and propagates through backbone area to other normal areas.
NSSA LSA—Type-7 LSA. Describes the route to a destination in another AS (external route.) Originated by ASBR in NSSA. ABR converts type-7 LSAs to type-5 LSAs for injection into the backbone area.