OSPF LSA Types
Terms
undefined, object
copy deck
- LSA Type 1
- Router LSA - Includes a list of directly attached link, identified by IP prefix assigned to link, and the RID of the originating router. Floods within area only, does not cross ABR.
- LSA Type 2
- Network LSA - Lists each of the attached routers that make up the transit network. Ethernet is an example where the DR makes the announcement. They never cross an area boundary.
- LSA Type 3
- Summary LSA - ABR sends type 3's which advertise any network owned by an area to the rest of the areas.
- LSA Type 4
- Summary LSA - Used only when ASBR exists and provides a route to it. The type 4 is learned by the ABR from the ASBR.
- LSA Type 5
- External LSA - Describe routes to networks outside the OSPF AS. Originated by the ASBR and are flooded to the entire autonomous system.
- LSA Type 6
- Specializd LSAs that are used in multicast OSPF applications.
- Allows ASBRs, an addendum to the OSPF RFC, uses special LSA type 7
- Not So Stubby Area NSSA
- Labeled area 0, all other areas connect to this area to exchange and route information. Some properties as standard OSPF area.
- Backbone area
- The area does not accept information about routes external to the AS, such as routes from non-OSPF sources. If routers need to route to networks outside the AS they use a default route. Cannot contain ASBRs
- Stub Area
- Does not accept external autonomous system routes or summary routes from other areas internal to the autonomous system. If the route needs to send a packet to a network external to the area, it sends the packet using a default route. Cannot contain ASBRs
- Totally Stubby Area