OSPF LSA Types

The routers in each area generate one or more link state advertisements. The collection of LSA forms the link-state database. Each of the LSA types has a specific function. The LSA types are listed below:

Router LSA
Network LSA
Network Summary LSA
ASBR Summary LSA
AS External LSA

Router LSA:

Generated by each router in an area about all of its connected links. This LSA is flooded with in the area. To view use the command “show ip ospf database router”. The RIB of OSPF will show the routes marked with “O”

Network LSA:

Generated by DR on the multiaccess network about more info the attached routers. This LSA is flooded with in the area. To view use the command “show ip ospf database network”

Network Summary LSA:

Generated by ABR to website advertise the destination information of other areas. This LSA is flooded between the areas (inter-area). To view use the command “show ip ospf database summary”. The RIB of OSPF will show the routes marked with “O*IA”

ASBR Summary LSA:

Generated website by ABR to advertise the ASBR information. This LSA is flooded between the areas (inter-area). To view use the command “show check here ip ospf database asbr-summary”. It will inform which router is doing the external route more info redistribution.

AS External LSA:

Generated by ASBR to advertise the destination information of the external networks. To view use the command “show ip ospf database external”. The RIB of OSPF will show the routes marked with “O*E2” or “O*E1”