Editing Medium access control (section)

== Addressing mechanism ==
The local network addresses used in [[IEEE 802]] networks and [[FDDI]] networks are called ''[[MAC address]]es''; they are based on the addressing scheme that was used in early [[Ethernet]] implementations. A MAC address is intended as a unique serial number. MAC addresses are typically assigned to network interface hardware at the time of manufacture. The most significant part of the address identifies the manufacturer, who assigns the remainder of the address, thus providing a potentially unique address. This makes it possible for frames to be delivered on a network link that interconnects hosts by some combination of [[repeater]]s, [[Ethernet hub|hub]]s, [[Network bridge|bridge]]s and [[Network switch|switch]]es, but not by [[network layer]]  [[Router (computing)|router]]s. Thus, for example, when an [[Internet Protocol|IP]] packet reaches its destination (sub)network, the destination IP address (a layer 3 or network layer concept) is resolved with the [[Address Resolution Protocol]] for [[IPv4]], or by [[Neighbor Discovery Protocol]] (IPv6) into the MAC address (a layer 2 concept) of the destination host.

Examples of physical networks are [[Ethernet]] networks and [[Wi-Fi]] networks, both of which are IEEE 802 networks and use IEEE 802 48-bit MAC addresses.

A MAC layer is not required in [[full-duplex]] [[Point-to-point (telecommunications)|point-to-point]] communication, but address fields are included in some point-to-point protocols for compatibility reasons.