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.