Figure 66: Typical Multiarea OSPF Network Topology
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 66.
Figure 66: Typical Multiarea OSPF Network Topology
To configure a multiarea OSPF network shown in Figure 66, 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).