Once Apache for Bonjour is set up, companies can make all sorts of information available to new staff on web servers and announce it via Bonjour, so that users can find address databases, fax numbers, forms and other material without having to pose endless questions. Once these direction signs have been set up on the network, servers can happily change their IP addresses - Bonjour updates this information on the client side immediately. This saves administrators the fiddly task of telling each individual network user what has changed, and is reliable.
Bonjour uses in part well-known existing technologies, such as using APIPA to select a unique IP address without requiring the services of a DHCP server. One of the most important innovations, however, is the fact that on Bonjour devices, name allocation takes place without requiring a central DNS and allows devices to announce or discover services themselves. Apple's iTunes music player, for example, registers itself as a music server when a user shares his MP3 collection on the network and printers register themselves automatically - so you can set up a printer on a workstation without needing to know the printer's IP address.
The Apple development team's dream of a network to which you just connect new devices is gradually being fulfilled. But many peripheral devices with Ethernet connections do not have Bonjour. They include a DHCP client and, because there is an active DHCP server on most networks, they are assigned an IP address, but they then wait for the user to find out what IP address they are on and complete the set up process.
For example with DSL routers or WLAN access points – very often DSL routers are the home DHCP server, but in any case they are generally configured using a browser and the user needs to know their IP address to enter into the browser. Equipped with Bonjour, the Internet Explorer or Safari browsers would immediately list them so that the user could access them straight away without needing to know their IP.
Apple describes how to implement Bonjour in hardware and there is also a Bonjour mailing list, in which the developers offer assistance with problems, but firmware updates adding Bonjour functionality to older network devices are unlikely to be forthcoming.
You can get around this problem, however, by making use of a computer on which Bonjour is already set up and a little known function of Bonjour - with minimal effort, a computer can also announce other devices' services on the network. This saddles the network administrator with a little extra work, but it relieves his memory and makes it easier for network novices to find their bearings.