Looking Ahead

Autonomous systems can grow in size beyond the control of administrators. Service providers might find themselves with a large internal BGP mesh that is both cumbersome and inefficient to control. On the other hand, enterprise networks might grow in a manner that causes internal gateway protocols to struggle in keeping up with instabilities. Controlling large-scale autonomous systems lies in the art of dividing these large domains into smaller, more manageable entities. The following chapter offers concepts and techniques that can help providers and customers apply architectural designs to achieve structured routing inside their domains.