BSCI Exam Cram™ 2 (Exam 642-801)

OSPF Areas, Routers, and LSAs

The process of breaking up a single area into multiple smaller areas is also known as hierarchical design. OSPF can operate well in larger environments with a hierarchical routing design in which multiple areas span or link to the core backbone Area 0. In addition to the benefits mentioned in the introduction, network problems such as flapping can be isolated to smaller areas without an adverse effect on the backbone area due to excessive SPF recalculations. When designing an OSPF network, you need to establish which routers and links are to be included in the backbone and which ones are to be placed in each area.

As you know, an area is a logical grouping of network segments that consists of a single autonomous ...