58GLOSSARY
loop An event that occurs when two network devices are connected by more than one path, thereby causing packets to repeatedly cycle around the network and not reach their destination.
MAC Media Access Control. A protocol specified by the IEEE for determining which devices have access to a network at any one time.
MAC address Media Access Control address; also called hardware or physical address. A layer 2 address associated with a particular network device. Most devices that connect to a LAN have a MAC address assigned to them as they are used to identify other devices in a network. MAC addresses are 6 bytes long.
MDI Medium Dependent Interface. An Ethernet port connection where the transmitter of one device is connected to the receiver of another device.
multicast A packet sent to a specific group of endstations on a network.
NIC Network Interface Card. A circuit board installed in an endstation that allows it to be connected to a network.
POST Power On Self Test. An internal test that a Switch carries out when it is
protocol A set of rules for communication between devices on a network. The rules dictate format, timing, sequencing and error control.
repeater A simple device that regenerates LAN traffic so that the transmission distance of that signal can be extended. Repeaters are used to connect two LANs of the same network type.
router A device that provides WAN links between geographically separate networks.
RPS Redundant Power System. A device that provides a backup source of power when connected to a Switch.
segment A section of a LAN that is connected to the rest of the network using a switch or bridge.
