Switches

[edit]Switches

A n'work switch is a device that forward and filter 2 datagrams between ports (connected cables) based on the MAC addresses in the packets This is distinct from a hub in that it only forwards the packet to the port involved in the communications rather than all ports connected. Strictly speaking, a switch is not capable of routing traffic based on IP address which is necessary for communicating between network segment or within a large or complex LAN. Some switche are capable of routing based on IP addresses but are still called switche as a marketing term. A switch normally has numerous port, with the intention being that most or all of the network is connected directly to the switch, or another switch that is in turn connected to a switch.^[7]

Switch is a marketing term that encompasses and bridges, as well as devices that may distribute traffic on load or by application content . Switches may operate at one or more OSI model layers, including physical, data link, network, or transport (i.e., end-to-end). A device that operates simultaneously at more than one of these layers is called a multilayer switch.

Overemphasizing the ill-defined term "switch" often leads to confusion when first trying to understand networking. Many experienced network designers and operators recommend starting with the logic of devices dealing with only one protocol level, not all of which are covered by OSI. Multilayer device selection is an advanced topic that may lead to selecting particular implementations, but multilayer switching is simply not a real-world design concept.