Each website requires a unique IP address. IP address depletion became a serious problem in the 1990s until new methods utilized available technology to maximize the number of IP addresses available. These methods included route aggregation, a process that generates a specific route and controls how networks make announcements for available routes.
Route aggregation tries to organize a network by replacing multiple routes with a single, general route. This process uses a hierarchical categorization that gives preference to addresses based on predetermined criteria. Aggregating routes limits the number of routes available to service providers. When a service provider receives IP addresses, the allocation of these IP addresses occurs in a contiguous block. The service provider can then divide the IP addresses into smaller allocated blocks and lease them to other Internet service providers.
Classless Inter-Domain Routing eliminated the need to use class-based IP address schemes. Implementation of this hierarchical addressing process resulted in large blocks of IP addresses divided and allocated to downstream ISPs. The allocation remains governed By Internet registries and the Internet Assigned Number Authority. These organizations make blocks available to different regional authorities around the world. These regions include the Americas, Europe and Asia, and the regions then allocate blocks of IP addresses within respective geographic regions to ISPs.
Organizational networks also used route aggregation to make network traffic more efficient. Organizations with geographically dispersed branches require networks that allow remote users and partners to integrate into the centralized corporate network. A modular aggregation router helps to facilitate this process by connecting routers with multiple network access points. Wide area network aggregation routers also provide more flexibility, scalability and security.
Route aggregation offers stability to networks. Additionally, reducing the number of routers minimizes the overhead related to routing protocols and reduces the number of updates required as a result of network changes such as upgrades or downgrades. Aggregation also reduces workload on the system by requiring less power, memory, storage and bandwidth.