What are different types of stub areas in OSPF

OSPF relies on several types of Link State Advertisements (LSAs) to communicate link state information between neighbors. A brief review of the most applicable LSA types:

  • Type 1 – Represents a router
  • Type 2 – Represents the pseudonode (designated router) for a multiaccess link
  • Type 3 – A network link summary (internal route)
  • Type 4 – Represents an ASBR
  • Type 5 – A route external to the OSPF domain
  • Type 7 – Used in stub areas in place of a type 5 LSA