Cisco ENCOR Practice Exam 2026 – All-in-One Comprehensive Guide to Mastering Enterprise Network Core Technologies!

The backbone area in OSPF (Open Shortest Path First) is always identified as Area 0. This area serves as the core of the OSPF network and is responsible for the efficient routing of information between other OSPF areas. All other areas must connect to the backbone area, making it essential for the overall structure and functioning of OSPF.

Area 0 facilitates the exchange of routing information between different areas, ensuring that routers can maintain a consistent and coherent view of the network. If a router has interfaces in multiple areas, at least one of those interfaces must connect to Area 0. This design helps to reduce routing complexity and maintains the hierarchy that OSPF is built upon.

Other areas, such as Area 1 and Area 2, do not have the inherent responsibilities that Area 0 does and could operate as non-backbone areas, potentially leading to fragmented routing without proper connectivity to the backbone. Thus, only Area 0 serves as the backbone area, reinforcing its crucial role in OSPF network design.