The area is a collection of routers that can be composed of no more than 80 routers, since if there is a larger collection of routers that make up the area, the learning and operation of routes may not be as stable, which is why it is recommended that If there is a large collection of routers in the AS, they are divided into areas so that there are ABRs between areas that allow the transition and learning of routes without problems.

The concept of “area” in the OSPF (Open Shortest Path First) protocol is fundamental to understanding how this routing technology manages and optimizes network traffic. OSPF is a dynamic link-state-based routing protocol used in IP networks, designed to scale efficiently in networks of all sizes, from small networks to large-scale backbone networks.

OSPF Area Definition

An OSPF area is a logical grouping of hosts and networks (router interfaces) that share the same Link-State Database (LSDB). The purpose of dividing a network into OSPF areas is to reduce the size of the link state database and minimize routing update traffic, which in turn reduces the load on routers and improves network efficiency.

How It Works

• OSPF Hierarchy: OSPF uses a hierarchy that divides networks into smaller areas to optimize routing updates. All areas must connect to a backbone area (called area 0 or backbone area) directly or through a virtual tunnel. The backbone area acts as an intermediary for traffic between areas.
• LSDB and SPF: Within a given area, all OSPF routers maintain an identical copy of the link state database for that area and use the Shortest Path First (SPF) algorithm to calculate the most efficient routes within the area. the area.
• Types of Areas: There are several types of areas in OSPF, including backbone area (0), stub areas, fully stub areas, and NSSA (Not So Stubby Area) areas. Each area type is designed to handle certain types of routing traffic and specific use cases to further optimize the network.

Benefits of Using Areas in OSPF

• Scalability: It allows OSPF to scale to handle large networks by dividing them into more manageable areas.
• Efficiency: It reduces the amount of routing information that must be processed and sent on the network, thereby decreasing the bandwidth needed for routing updates and CPU usage on routers.
• Speed ​​in Convergence: Minimizes convergence time following a change in network topology, as changes are often confined to a single area.
• Traffic control: Allows greater control over routing traffic and the application of routing policies.

The design and implementation of OSPF areas must be done carefully to maximize performance and scalability benefits while keeping network operations simplified and efficient.