Chapter 15 / 15.5 / 15.5.5

15.5.5 Choosing The Best Route

The Internet is often described as a "network of networks."

Rather than being operated by a single organization, it consists of many thousands of independently managed Autonomous Systems interconnected through routers.

Each organization manages its own internal routing while exchanging summarized routing information with neighbouring organizations through BGP.

This hierarchical approach allows the Internet to scale efficiently despite its enormous size. Individual routers do not require detailed knowledge of every network in the world. Instead, each router forwards packets using the routing information appropriate to its position within the overall Internet architecture.