Ethernet: The Definitive Guide, 2nd Edition

Chapter 19. Network Design with Ethernet Switches

In this chapter, we will show some of the basic ways in which switches can be used to build an Ethernet system. Network design is a large topic, and there are many ways to use switches to expand and improve networks. We will focus on just a few basic designs here, with the goal of providing a brief introduction to network design with Ethernet switches.

Advantages of Switches in Network Designs

Switches provide multiple advantages in network designs. To begin with, all switches provide the basic traffic filtering functions described in the previous chapter, which improves network bandwidth. Another important advantage of modern switches is that the internal switching electronics allow different traffic flows to occur simultaneously between multiple ports. Supporting multiple simultaneous flows of traffic, or “conversations,” between the ports is a major advantage of switches in network designs.

Improved Network Performance

An important way in which a switch can improve the operation of a network system is by controlling the flow of traffic. The ability to intelligently forward traffic on only those ports needed to get the packet to its destination makes the switch a useful tool for the Ethernet designer faced with continually growing device populations and increasing traffic loads.

The traffic control provided by the internal address database can be exploited to help isolate traffic. By locating client and server connections on switches ...