OSPFv3 Link-state advertisement (LSA) types

OSPFv3 uses LSAs transmitted by each router to update neighboring routers regarding its interfaces and the routes available through those interfaces.

Each routing switch in an area also maintains an LSDB that describes the area topology. (All routers in a given OSPFv3 area have identical LSDBs, and each router uses the LSDB to build its own shortest-path tree.)

The routing switches used to connect areas to each other flood inter-area-prefix-LSAs, inter-area-router-LSAs, and AS-external-LSAs to backbone area to update it regarding available routes. Each OSPFv3 router determines the shortest path between itself and a desired destination router in the same OSPFv3 domain (AS). Routed traffic in an OSPFv3 AS is classified as one of the following:
  • Intra-area traffic

  • Inter-area traffic

  • External traffic

The routing switches support the LSAs listed in the following table.

Link-state type Description Use Flood scope
0x2001 Router-LSA

Describes the state of each active interface on a router for Area a given area. (Excludes loopback interfaces and interfaces that have not achieved full adjacency.)

0x2002 Network-LSA

Describes the OSPFv3 routers in a given network.

0x2003 Inter-area-prefix-LSA

Describes the route to a prefix in another OSPFv3 area of Area the same AS. (Excludes prefixes for link-local addresses.)

Propagated through backbone area to other areas.

0x2004 Inter-area-router-LSA

Describes the route to an ASBR in another OSPFv3 normal area (including the backbone area) of the same AS.

Propagated through backbone area to other areas. (Excludes any ASBR in the same area as the router sending the LSA.)

0x4005 AS-external-LSA

Describes the route to a destination prefix in another AS (external route). (Excludes prefixes for link-local addresses.) Originated by ASBR in normal or backbone areas of an AS and propagates through backbone area to other normal areas.

Does not flood over virtual links and is not summarized in virtual links. For injection into an NSSA, an NSSA ABR generates a type-7-default-LSA advertising the default route (::/0).

0x2007 NSSA-LSA

Describes the route to a destination in another AS (external route). Originated by ASBR in NSSA. ABR translates type-7 LSAs to AS-external-LSAs for injection into the backbone area.

0x0008 Link-LSA

For other routers on the same VLAN interface (except virtual links), describes the router link-local address and any other IPv6 prefixes reachable on the VLAN. Link LSAs are not flooded over virtual links.

0x2009 Intra-area-prefix-LSA

Generated on transit links within an area by the DR operating on those links. Also, every OSPFv3 router generates this LSA to refer to stub and loopback prefixes on the router.