This chapter covers the following topics, which you need to understand to pass the CCNP/CCDP/CCIP BSCI exam:
The purpose of using OSPF in a multiple area network
The features of multiple area OSPF
The operation of OSPF across multiple areas
Design considerations in multiple area OSPF
The topics in this chapter detail the routing protocol OSPF across multiple areas. This chapter assumes your knowledge of Chapter 6, "Using OSPF in a Single Area," and Chapter 7, "Configuring OSPF in a Single Area," which dealt with OSPF concepts and configuration in a single area. Chapter 8 builds on this understanding and explains how OSPF works within a large multiarea network. This chapter and the following chapter cover two major sections. Chapter 8 deals with how the protocol works theoretically. Chapter 9, "Configuring OSPF Across Multiple Areas," covers how to implement and manage an OSPF network. This chapter introduces OSPF areas and explains the operation of the protocol across those areas.
Before you can configure OSPF in multiple areas, you need to understand the motivation for using OSPF in multiple areas. You then must understand how to determine the area boundaries in OSPF. In order to design a multiarea OSPF network in this way, you need a comprehensive grasp of the features of multiarea OSPF, the operation of OSPF across multiple areas and, of course, the design considerations of such a network. This chapter discusses each of these topics.