To reduce traffic and topology maintenance for the Services Routers in an OSPF autonomous system (AS), you can group them into multiple areas, as shown in Figure 74.
Figure 74: Typical Multiarea OSPF Network Topology
To configure a multiarea OSPF network shown in Figure 74, perform the following tasks on the appropriate Services Routers in the network. You must create a backbone area. To link each additional area to the backbone area, you must configure one of the Services Routers as an area border router (ABR).