OSPF Area Types – Different Areas in OSPF are used to create smaller fault domains. There are two OSPF area types in total.
OSPF Backbone area and OSPF non-backbone area
Backbone area in OSPF is Area 0. OSPF prevents loop by using backbone area concept.All the non-backbone areas should be connected to the Backbone area.
There are many Non-Backbone OSPF Area types. These are; Normal Area, Stub, Totally Stub, NSSA and Totally NSSA Areas.
In this article I will explain the non-backbone OSPF areas from the design point of view and share some caveats about the OSPF design.