All bonjour and other zeroconf services are designed to be specifically local with a TTL of 1 meaning that they will never pass beyond a router, Which in a home environment is ideal in that your neighbors or anyone else that might have access to your network upstream cannot access the zeroconf services behind your router. But in a enterprise environment, this is a great limitation to its implementation as it is impossible to use bonjour across subnets.

Enter the Bonjour Gateway, essentially it is a re-trans station for bonjour services allowing devices on one side of the subnet boundaries to see the services available on the other.

This how-to will allow you to build your own Bonjour Gateway allowing you to use AirPlay, AirPrint and other Bonjour/ZeroConf Services across the different subnets in your environment.

It may be deployed in any hardware/ virtual environment that you choose. in our environment I built it into a small low power appliance using an EeePC box that had otherwise outlived its usefulness.