The goal in designing networks is to maximize reliability while minimizing cost. These are usually conflicting goals and tradeoffs must be made. This is cost effective and provides an easy way to troubleshoot problems. Build networks that whereever possible servers and clients are on the same network. Use routers to build enterprise networks.
Routers are more effective at isolating and controlling traffic among networks.
Use bridges to seperate traffic within a network. If you are not sure of the type of cable you will be connecting it is wise to purchase machines with an AUI interface and then use transceivers to connect the machine to whatever media you have. Before designing networks make sure you understand and follow the design limitations for each media type you use. For that reason it is Stongly recommended you adhere to the standards.