1.1 The Hierarchical Network Design Model  
  1.1.2 Router function in the hierarchy  
The core, distribution, and access layers each have clearly defined functions. For this reason, each layer demands a different set of features from routers, switches, and links. Routers that operate in the same layer can be configured in a consistent way because they all must perform similar tasks. The router is the primary device that maintains logical and physical hierarchy in a network. Therefore, proper and consistent configurations are imperative. Cisco offers several router product lines. Each product line has a particular set of features for one of the three layers:
  • Core layer – 12000, 7500, 7200, and 7000 series routers.
  • Distribution layer – 4500, 4000, and 3600 series routers.
  • Access layer – 2600, 2500, 1700, and 1600 series routers.

The following sections revisit each layer and examine the specific routers and other devices used.

 

Interactive Media Activity

Drag and Drop: Defining the Role of the Router in the Hierarchy

In this media activity, the student will identify the functions of each hierarchy layer.

   
 

Web Links

Internetworking Design Basics

http://www.cisco.com/univercd/cc/td/doc/ cisintwk/idg4/nd2002.htm