Communication between switches and workstations

Communication between switches and workstations 
4.3.9 This page will explain how switches learn about workstations in a LAN.
When a workstation connects to a LAN, it is unconcerned about the other devices that are connected to the LAN media. The workstation simply transmits data frames using a NIC to the network medium.
The workstation could be attached directly to another workstation using a crossover cable. Cross-over cables are used to connect the following devices:

• Workstation to Workstation
• Switch to Switch
• Switch to hub
• Hub to hub
• Router to router
• Router to PC

Straight-through cables are used to connect the following devices:

• Switch to router
• Switch to workstation or server
• Hub to workstation or server

Switches are Layer 2 devices that use intelligence to learn the MAC addresses of the devices that are attached to the ports of the switch. This data is entered into a switching table. Once the table is complete, the switch can read the destination MAC address of an incoming data frame on a port and immediately forward it. Until a device transmits, the switch does not know its MAC address.
Switches provide significant scalability on a network and may be directly connected. Figure illustrates one scenario of frame transmission utilizing a multi-switch network.
This page concludes this lesson. The next page will summarize the main points from this module.