OSPF Interview Questions & Answer Part-2 | OSPF LSA,s & Special Area Types

During my last blog of OSPF Part-1, I explained about OSPF Packet types and states. Now I will explain about LSA & OSPF Special area types Interview questions & answer summary.
OSPF LSAs Types:

Now let me summarize the answers to the above LSA-related questions.
Router LSA-1 of OSPF contains the connected interface information & this LSA is advertising in same area only. It will not cross to other areas means No inter-area details.
Network LSA-2 is also advertising in the same area of OSPF. But this LSA is advertised by a designated router (DR). All connected link information of all routers in the same Networks are distributed by DR to all DR others.
Summary LSA-3 is used for inter-area communication. This LSA contains details of the local area & advertised to other areas by Area border router (ABR).by this way all nodes in the OSPF domain learn different area routes & reachable to each other.
Summary ASBR LSA-4 is used to find the location of ASBR. This LSA-4 is advertised by ABR not ASBR. The more interesting thing that I mentioned in the above Question as well that all routes in the same area where ASBR is not receive LSA-4 but they received LSA-1 or LSA-2 to find the location of ASBR because they all are in the same area.
External LSA-5 is used by ASBR to advertise the redistributed/imported routes to all other areas in the same domain. For example, if some other protocol i-e RIP, BGP, static, or multiple processes of OSPF in the same router running then in this case we redistribute/import those routes to OSPF, these all routes are advertised in LSA-5.
Multicast LSA-6, before OSPF was tried to use for multicast traffic like nowadays PIM & other protocols are used.in those days LSA-6 was used for multicast services but now no use.
NSSA External LSA-7 is an external LSA using in one special area type NSSA that I will explain later in this post in detail with examples.
External attribute LSA for BGP LSA-8 when we import/redistribute BGP into OSPF on ASBR router, then during this process BGP attributes/features are lost. To maintain & carry BGP attributes in OSPF Domain LSA-8 is used.
Opaque LSA-9/10/11. These LSAs carry some extra feature information in MPLS TE & the latest technology Segment Routing (SR) & SRV6.I will explain this in a later MPLS/SR topic.
Next post I will continue to explain OSPF Special area types.
Keep Reading, Learning & sharing the knowledge.