Switch
A switch is
setup and looks similar to a shared hub. The difference
is each port on the switch is considered a
segment
and has dedicated bandwidth (10Mbps or 100 Mbps). Data is
not sent out of a port/segment unless meant for a device
on another port/segment. None of the other computers on
the other segments have to "hear" or be slowed by
the traffic. Conversely a computer on a shared hub
"hears" all sent data from every other connected
computer.
See
the illustrated explanation of how a shared hub
works.
A switch
works by building a table that keeps track of what
devices are on each segment. When data flows through the
switch, the table is referenced to see which port/segment
to send it down.
Let us say
computer A is on one port, the printer is on
another, computer B is on a third port and the server is
on the fourth. On a switch, Computer A can send a print
job at the same time computer B accesses the
server.
See
the illustrated explanation of how a switch
works.
Whenever a
device connected to the LAN switch sends a packet to an
address that is not in the LAN switch's table or whenever
the device sends a broadcast or multicast packet, the
switch sends
the
packet out all ports. This is referred to as flooding.
Therefore, multicasts and broadcasts will slow even a
"switched" network.
