The structured engineering principles of good network design include hierarchy, modularity, resiliency, and flexibility.
A typical enterprise hierarchical LAN campus network design includes the access layer, distribution layer, and the core layer. In smaller enterprise networks, a “collapsed core” hierarchy, where the distribution layer and core layer functions are implemented in a single device, can be more practical. The benefits of a hierarchical network include scalability, redundancy, performance, and maintainability.
A modular design that separates the functions of a network enables flexibility and facilitates implementation and management. The basic module blocks that are connected by the core include the access distribution block, the services block, the data center, and the enterprise edge. The Cisco Enterprise Architecture modules are used to facilitate the design of large, scalable networks. The primary modules include the enterprise campus, enterprise edge, service provider edge, enterprise data center, enterprise branch, and enterprise teleworker.