Because of the complexity and widespread use of OSPF,
knowledge of its con?¬?guration and maintenance is essential. This chapter describes the function
of OSPF and explains how to con?¬?gure a single-area OSPF network on a Cisco router.
Chapter Objectives
Upon completing this chapter, you will be able to describe the operation and con?¬?guration of a
single-area OSPF network, including load balancing and authentication. This ability includes
being able to meet these objectives:
?– Describe the features of OSPF
?– Describe how OSPF neighbor adjacencies are established
?– Describe the SPF algorithm that OSPF uses
?– Con?¬?gure a single-area OSPF network
?– Con?¬?gure a loopback interface to be used as the router ID
?– Verify a single-area OSPF network con?¬?guration
?– Use the OSPF debug commands to troubleshoot OSPF
?– Con?¬?gure load balancing with OSPF
?– Con?¬?gure authentication for OSPF
Introducing OSPF
Open Shortest Path First is a link-state routing protocol. You can think of a link as an interface
on a router. The state of the link is a description of that interface and of its relationship to its
neighboring routers. A description of the interface would include, for example, the IP address
140 Chapter 4: Single-Area OSPF Implementation
of the interface, the subnet mask, the type of network to which it is connected, the routers that are
connected to that network, and so on.
Pages:
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224