OSPF LSA types

Link-State Advertisements

• Router link (type 1) - Lists a router's neighbors and its cost to each; flooded throughout the area. Используется в пределах area
• Network link (type 2) - Advertisement by the DR containing all routers on the segment it is adjacent to; flooded throughout the area
• Network summary link (type 3) - ABRs generate this type of LSA to send between areas; it lists all prefixes available in an are.Используется для анонсов из одной area в другую.
  
• AS external ASBR summary link (type 4) - Router link LSA for ASBRs. Анонс IP ASBR.
• External link (type 5) - Originated by an ASBR, contains a route external to OSPF
• NSSA external (type 7) - Equivalent to a type 5 LSA, but generated by an ASBR in a not-so-stubby area (NSSA); converted to a type 5 by the ABR