|
|
4.3 | |
Switch Operation | |
| 4.3.10 | |
Communication between switches and workstation |
| 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 or attached to
a network device, such as a hub, switch, or router, using a
straight-through cable.
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.
Switches provide significant scalability
on a network and may be directly connected. Figure
|
Until a
device transmits, the switch does not know its MAC address.
illustrates
one scenario of frame transmission utilizing a multi-switch
network.