Bonjour Network Configuration Services

Steve Jobs Introduces Front Row and Bonjour Software (2006)
Steve Jobs Introduces Front Row and Bonjour Software (2006). Peter DaSilva / Getty Images

Bonjour is an automatic network discovery technology developed by Apple, Inc. Bonjour allows computers and printers to automatically find and connect to each other's services using a new communication protocol, saving time and simplifying tasks such as file sharing and setting up of network printers. The technology is based on Internet Protocol (IP), allowing it to work with both wired and wireless networks.

Capabilities of Bonjour

Bonjour technology manages network shared resources as types of services. It automatically discovers and keeps track of the locations of these resources on a network as they come online, go offline, or change IP addresses. It also provides this information to network applications to allow users to access the resources.

Bonjour is an implementation of zeroconf - Zero-configuration networking. Bonjour and zeroconf support three key discovery technologies:

  • address assignment
  • name resolution
  • location services

Bonjour uses a link local addressing scheme for automatically assigning IP addresses to local clients without the need for Dynamic Host Configuration Protocol (DHCP).. It works with both IPv6 and legacy IP (IPv4) addressing schemes. On IPv4, Bonjour utilizes the 169.254.0.0 private network like Automatic Private IP Addressing (APIPA) on Windows, and uses the native link local addressing support in IPv6.

Name resolution in Bonjour works via a combination of local host name configuration and multicast DNS (mDNS). While the public Internet Domain Name System (DNS) relies on outside DNS servers, multicast DNS works within a local network and enables any Bonjour device on the network to receive and respond to queries.

To provide location services to applications, Bonjour adds a layer of abstraction on top of mDNS to maintain browsable tables of Bonjour enabled applications organized by service name.

Apple took special care with the implementation of Bonjour to ensure its network traffic did not consume an excessive amount of network bandwidth. In particular, the mDNS includes caching support for remembering recently requested resource information.

For more information, see Bonjour Concepts (developer.apple.com).

Bonjour Device Support

Apple computers running newer versions of Mac OS X support Bonjour as a capability embedded in various network applications such as the Web browser (Safari), iTunes and iPhoto. Additionally, Apple provides a Bonjour service for Microsoft Windows PCs as a free software download on apple.com.

How Applications Work with Bonjour

Several Bonjour Browser applications (either downloadable client software for desktop and laptop computers, or phone and tablet apps) have been created that allow network administrators and hobbyists to browse information about Bonjour services advertising themselves on active networks.

Bonjour technology offers a set of Application Programming Interfaces (APIs) for both macOS and iOS applications plus a Software Development Kit (SDK) for Windows applications.

 Those with Apple Developer accounts can access additional information Bonjour for Developers.