Cisco WS-C3560G-48TS-S 3560 48-Port
Multilayer Gigabit Ethernet Switch
A network switch operates at layer 2, the data link layer of the OSI
model. It records the MAC (Media Access Control) addresses of the devices attached
to its ports. When a frame is received intended for a device connected to one of
its ports, it sends that frame only to that device, thereby reducing network traffic.
A multilayer switch also works at layer 3, the network layer of the
OSI model. That's why a multilayer switch is sometimes called a layer 3 switch.
At layer 3, data is encapsulated into packets containing the destination IP
address. This allows the switch to also perform routing between subnets, which further
optimizes network traffic.
The term multilayer means the switch operates at multiple layers of the OSI
Model. Today there are multilayer switches that use information in layer 4 segments and
protocol data units all the way up to layer 6 of the OSI model.