OSPF LSA Types

  • Type 1: Router LSA
  • Type 2: Network LSA  (Generated by DR)
  • Type 3: Summary LSA (ABR Summary route)
  • Type 4: Summary LSA (ASBR location)
  • Type 5 External (ABSR Summary route)

Stubby Area: Blocks type 5 LSAs from entering. To enable: “area x stub”

Totally Stubby Area: Blocks type 3, 4 and 5 LSAs from entering (Cisco Proprietary although only ABR needs to be a Cisco device).  To enable: “area x stub no-summary”

Not-So-Stubby Area (NSSA): Passes external routes via Type 7 LSAs; These convert back to Type 5 once they reach the backbone. To enable: “area x nssa”

Totally Not-So-Stubby Area (NSSA): Passes external routes via Type 7 LSAs; These convert back to Type 5 once they reach the backbone.  Types 3, 4, and 5 are still filtered as per a Totally Stubby area.  To enable: “area x nssa no-summary”

 

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