 | Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |
OSPF is enabled on a per-interface basis. Those interfaces are configured as OSPF enabled, and are assigned to an area. In a simple, single-area network, the area has the numeric identifier 0.0.0.0, which designates it as the backbone area. As the network grows, it is divided into multiple subnetworks or areas that are identified by numeric identifiers unique to the AS.
In a multiarea network, all areas must be directly connected to the backbone area by area border routers (ABRs). Because all areas are adjacent to the backbone area, OSPF routers send all traffic not destined for their own area through the backbone area. The ABRs in the backbone area are then responsible for transmitting the traffic through the appropriate ABR to the destination area.
| Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |