Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...

's Bonjour Sleep Proxy service is an open source component of

zero-configuration networking Zero-configuration networking (zeroconf) is a set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manu ...

, designed to assist in reducing power consumption of networked electronic devices. A device acting as a sleep proxy server will respond to

Multicast DNS In computer networking, the multicast DNS (mDNS) protocol resolves hostnames to IP addresses within small networks that do not include a local name server. It is a zero-configuration service, using essentially the same programming interfaces, pac ...

queries for another compatible device which has gone into low power mode. The ''low-power-mode'' device remains ''asleep'' while the sleep proxy server responds to Multicast DNS queries. When the sleep proxy server sees a query which requires the ''low-power-mode'' device to ''wake up'', the sleep proxy server sends a special wake-up-packet ("magic packet") to the low-power-mode device. Finally, communication parameters are updated via Multicast DNS, and normal communications proceed. Apple refers to the service as Bonjour Sleep Proxy in its support documents. The service supports the Wake on Demand feature, first offered in

Mac OS X Snow Leopard Mac OS X Snow Leopard (version 10.6) is the seventh major release of macOS, Apple's desktop and server operating system for Macintosh computers. Snow Leopard was publicly unveiled on June 8, 2009 at Apple’s Worldwide Developers Conference. ...

Details

Address resolution protocol

The sleep proxy service responds to

address resolution protocol The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function ...

requests on behalf of the low-power-mode device:

When a sleep proxy sees an IPv4 ARP or IPv6 ND Request for one of the sleeping device's addresses, it answers on behalf of the sleeping device, without waking it up, giving its own MAC address as the current (temporary) owner of that address.

This may appear confusing to network administrators who are not expecting the behaviour of changing

MAC addresses A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking techno ...

Wireless magic packet

In case the low-power-mode device is communicating via

Wi-Fi Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wav ...

, the wake-up-packet is sent via

Wireless Multimedia Extensions Wireless Multimedia Extensions (WME), also known as Wi-Fi Multimedia (WMM), is a Wi-Fi Alliance interoperability certification, based on the IEEE 802.11e standard. It provides basic Quality of service (QoS) features to IEEE 802.11 networks. WMM ...

(WMM). This was not possible in previous implementations of Wake on LAN (WoL). The wireless hardware must be updated enough to include WMM support. Apple provides instructions for checking compatibility with this feature for Macintosh computers.

Supported services and examples

The sleep proxy service is able to advertise any Bonjour-supported services, while the host computer sleeps. Some examples of supported services are: *

File sharing File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include r ...

: a host supporting the sleep proxy service, which offers file services, may go to sleep as needed. When someone needs to access shared files, the host will wake up automatically. * iTunes library sharing: the computer hosting the iTunes library may go to sleep, and will automatically wake when someone wishes to browse the iTunes library from a different PC. * Printer sharing: a printer may be connected and shared from a computer supporting sleep proxy service. The computer can go to sleep when not in use, but will wake when needed to service a print job being sent from a different computer. *

SSH The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH applications are based on ...

: a computer offering SSH access may go to sleep, and awaken via the sleep proxy service when an SSH login is initiated. *

Desktop sharing Desktop sharing is a common name for technologies and products that allow remote access and remote collaboration on a person's computer desktop through a graphical terminal emulator. The most common two scenarios for desktop sharing are: * Remot ...

: similar to above examples.

Implementations

''Implementations on a

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...

can be seen with

Bonjour Browser Bonjour is Apple's implementation of zero-configuration networking (zeroconf), a group of technologies that includes service discovery, address assignment, and hostname resolution. Bonjour locates devices such as printers, other computers, and ...

.'' * Apple

AirPort An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports usually consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surfa ...

Express with firmware version 7.4.1 or 7.4.2 * Apple

Extreme with firmware version 7.4.1 or 7.4.2 * Apple

Time Capsule A time capsule is a historic cache of goods or information, usually intended as a deliberate method of communication with future people, and to help future archaeologists, anthropologists, or historians. The preservation of holy relics dates ...

* Apple TV (all generations) *

HomePod The HomePod is a smart speaker developed by Apple Inc. The HomePod was designed to work with the Apple Music subscription service. The HomePod was announced on June 5, 2017, at the Apple Worldwide Developers Conference. Its launch was later d ...

(2018) * HomePod mini (2020) * Computers running

act as a Bonjour sleep proxy server when

Internet sharing Internet Connection Sharing (ICS) is a Windows service that enables one Internet-connected computer to share its Internet connection with other computers on a local area network (LAN). The computer that shares its Internet connection serves as a ...

is enabled.Apple Inc.

Worldwide Developers Conference The Worldwide Developers Conference (WWDC) is an information technology conference held annually by Apple Inc. The conference is usually held at Apple Park in California. The event is usually used to showcase new software and technologies in t ...

(WWDC) 2009, Session 508, ''Zero Configuration Networking Using Bonjour''

References

External links

* , see ''Mosaics'' tab for figures * , see ''Mosaics'' tab for figures * {{Cite patent, country=US, number=7447757, see ''Mosaics'' tab for figures
Fscklog.com: Snow Leopard und 2009er Macs: Wake on WLAN (German, Deutsch)

Macrumors.com: A Closer Look at Snow Leopard's Wake on Demand Feature

opensource.apple.com: Open-source mDNS implementation including the sleep proxy service

UC San Diego: SleepServer: A Software-Only Approach for Reducing the Energy Consumption of PCs within Enterprise Environments
22 June 2010. Usenix 2010.
Microsoft Research: Sleepless In Seattle No Longer
22 June 2010. Usenix 2010. *

Stuart Cheshire Stuart Cheshire is a Distinguished Engineer, Scientist and Technologist (DEST) at Apple. He pioneered Zeroconf networking while employed at Apple. Zeroconf was originally released by Apple as Rendezvous, but later renamed Bonjour. Subsequently, h ...

has a page describing steps fo
troubleshooting Sleep Proxy Service
Apple Inc. software Computer configuration Domain Name System Link protocols Network protocols Windows communication and services