Understanding the problem domain
We start modeling the problem domain by considering the fact that a core router can connect to both core and edge routers. Edge routers, in turn, connect to switches and their networks. The following diagram depicts this scenario:
Figure 6.2 – A use case for the topology and inventory network system
Core routers are faster and deal with high traffic loads, and they don't deal directly with the traffic generated from a switch and its networks. On the other hand, edge routers deal directly with traffic generated by a switch and its networks. In our scenario, an edge router is not allowed to connect to other edge routers; it can only connect to core routers and switches. A switch can have multiple networks.
Bear in mind that's a particular arrangement established for our scenario. By no means does it represent a strict rule of how to organize network components. Here is a diagram showing the arrangement...
