Description: Specifies an OSPF area type: normal areas are defined as areas that can accept intra-area, inter-area and external routes. stub areas do not accept routes belonging to external autonomous systems (AS); however, these areas have inter-area and intra-area routes. This reduces the size of the routing databases for the area's internal routers. Routers in the stub area also contain a default route which is advertised to the area by the Area Border Router (ABR). totallyStub areas do not allow routes other than intra-area and the default route to be propagated within the area. This further reduces the size of the routing databases for the area's internal routers. The ABR advertises a default route into the area and all the routers belonging to this area use the default route to send any traffic outside the area. nssa (Not So Stub Areas) can import AS external routes from within the area and send them to other areas, but cannot receive AS external routes from other areas. Inter-area and intra-area routes are allowed along with a default route which is advertised to the area by the ABR. nssaTotallyStub areas are similar to nssa with the added restriction that inter-area routes are not allowed.