Editing Zero-configuration networking (section)

==Background==
Computer networks use numeric [[network address]]es to identify communications endpoints in a network of participating devices. This is similar to the [[Plain old telephone service|telephone network]] which assigns a string of digits to identify each telephone. In modern [[networking protocol]]s, information to be transmitted is divided into a series of [[network packet]]s. Every packet contains the source and destination addresses for the transmission. [[Network router]]s examine these addresses to determine the best network path in [[Packet forwarding|forwarding the data packet]] at each step toward its destination.

Similarly to telephones being labeled with their telephone number, it was a common practice in early networks to attach an address label to networked devices. The dynamic nature of modern networks, especially residential networks in which devices are powered up only when needed, desire dynamic address assignment mechanisms that do not require user involvement for initialization and management. These systems automatically give themselves common names chosen either by the equipment manufacturer, such as a brand and model number or chosen by users for identifying their equipment. The names and addresses are then automatically entered into a [[directory service]].

Early computer networking was built upon technologies of the telecommunications networks and thus protocols tended to fall into two groups: those intended to connect local devices into a [[local area network]] (LAN), and those intended primarily for long-distance communications. The latter [[wide area network]] (WAN) systems tended to have centralized setup, where a [[network administrator]] would manually assign addresses and names. LAN systems tended to provide more automation of these tasks so that new equipment could be added to a LAN with a minimum of operator and administrator intervention.

An early example of a zero-configuration LAN system is [[AppleTalk]], a protocol introduced by [[Apple Inc.]] for the early [[Macintosh computer]]s in the 1980s. Macs, as well as other devices supporting the protocol, could be added to the network by simply plugging them in; all further configuration was automated. Network addresses were automatically selected by each device using a protocol known as AppleTalk Address Resolution Protocol (AARP), while each machine built its own local directory service using a protocol known as Name Binding Protocol (NBP). NBP included not only a name but the type of device and any additional user-provided information such as its physical location or availability. Users could look up any device on the network with the application [[Chooser (Mac OS)|Chooser]], which filtered names based on the device type.

On [[Internet Protocol]] (IP) networks, the [[Domain Name System]] database for a network was initially maintained manually by a network administrator. Efforts to automate maintenance of this database, led to the introduction of a number of new protocols providing automated services, such as the [[Dynamic Host Configuration Protocol]] (DHCP).