Question :

I have a network printer on my (private) network that I would like to make available to the people on my AirPort Guest Network, but I don’t want guests to access my private network.

Is there a way to do this ?

Answer :

There are options to do this, but it can’t be done the way you would find most elegant probably… the problem is the restriction in AirPort Guest Networks that users can’t connect to each other, so adding the printer to the AirPort Guest Network won’t make it available to any AirPort Guest Network user.

On the other hand, an other restriction on most network printers is that they only have one Ethernet-card that is shared between the UTP-cable port and the WiFi connection, so the cable-connection and the WiFi-connection will always have the same IP-address, making it impossible to connect the cable to your private network and joining the Guest Network using the WiFi-connection at the same time…

Your best option is to connect the Ethernet/UTP-cable and/or the printer’s WiFi to your private network and creating a separate network to be used as a Guest Network to which the printer can be connected using it’s USB-cable. Since you will need an extra wireless router or an extra (secondhand) AirPort Base Station or Time Capsule to create this separate Guest Network, you can plug the printer’s USB-cable into that wireless router / AirPort Base Station / Time Capsule.

You could also use a printer server, if it isn’t possible to connect the printer’s USB-cable into the wireless router / AirPort Base Station / Time Capsule. You can find relatively cheap print servers on Amazon.com, Amazon.co.uk or Amazon.de

Regarding the setup of your networks, you will probably be best off doing it like this :

• set your internet modem in router mode (if you would set it in bridge mode, you wouldn’t be able to connect two separate networks behind it)
• connect both routers (or AirPort Base Station or Time Capsule) to the internet modem
• setup one router (or AirPort Base Station or Time Capsule) to create the private network and private WiFi network
• setup the other router (or AirPort Base Station or Time Capsule) to create the Guest Network and Guest WiFi Network
• make sure that the IP-ranges issued by both routers are completely different (to prevent easy connection from the Guest Network to your private network (and the other way around)
• if any of your routers give a “Double NAT” error, just ignore it

That’s it !

the only downsite is that having such a complex network setup with multiple routers will have negative influence on your (internet) connection speed ; this difference in speed will probably not be very big if you have few devices connected, but if you have a lot of devices connected that also use a lot of bandwidth (like video streaming) you will probably have slower internet speed than you used to…

enjoy !