Chapter 1. Hierarchical Design Principles

Your boss walks into your cube, throws a purchase order on your desk, and says, "Here, it's signed. Purchasing says a thousand routers are going to take up a lot of space over there, so you need to have your people pick them up as soon as they come in. Now make it work." Is this a dream or a nightmare?

It certainly isn't real—real networks start with two routers and a link, not with a thousand router purchase order. But a network with even ten routers is so small that network design isn't an issue. Right? Wrong. It's never too early to begin planning how your network will look as it grows.