what is nssa stubby totally stubby?
Not-so-stubby Areas An NSSA makes use of type 7 LSAs, which are essentially type 5 LSAs in disguise. This allows an ASBR to advertise external links to an ABR, which converts the type 7 LSAs into type 5 before flooding them to the rest of the OSPF domain. An NSSA can function as either a stub or totally stubby area.