A network switch (also called switching hub, bridging hub, and, by the IEEE , MAC bridge) is networking hardware that connects devices on a computer network by using packet switch to receive and forward data to the destination device.
A network switch is a multiport
network bridge
that uses
MAC addresses
to forward data at the
data link layer
(layer 2) of the
OSI Model
. Some switches can also forward data
at the
network layer
(layer 3) by
additionally incorporating
routing
functionality. Such switches are commonly known as layer-3 switches or
multilayer switches
.
Switches for Ethernet are the most common form of network switch.
Source: https://en.wikipedia.org/wiki/Network_switch
- Take advantage of MAC addresses to allow devices to communicate directly.
- At first a switch acts like a hub, forwarding all frames to all devices, but quickly creates a source address table (SAT) and only forwards to destination MAC addresses.
- Each device connection can run at full network speed.
- Unicast messages always go only to the intended recipient.
- All broadcast messages go to all ports except origin port.
Crossover Cables #
Switches can cannect to each other with these.
Spanning Tree Protocol #
Troubleshooting #
Obvious Physical Damage #
- Examine switch for physical damage.
- Replace any obviously damaged switches.
Dead Ports #
- look to see if port is flashing
- If not, try a different port.
- Try replacing or testing cable.