Guide to Mac-friendly wireless routers: AppleTalk support

CNET staff

Sept. 2, 2009 12:54 a.m. PT

2 min read

Some third-party wireless routers are unable to access AppleTalk devices (particularly printers) that are connected to the network. Below is an explanation of why some routers do not support AppleTalk, followed by a list of third-party devices that do.

This issue should never appear with Apple's AirPort base stations. If you are experiencing this issue with an AirPort unit, make sure that both your AirPort card and base station firmware (Dual-Ethernet, Express, Extreme) are up-to-date. Also, make sure you are running Mac OS X 10.4.7 or later.

The reason this problem (lack of AppleTalk support) manifests with some third-party wireless routers is that certain Ethernet packets (the individual units of data sent over the network) including IP-over-Ethernet use a specific format: 12 bytes of destination and source addresses, plus a two byte "type" field. AppleTalk packets, however, use a "SNAP" frame, which is a slightly different format.

All wireless 802.11 packets, those used by WiFi hardware, are actually SNAP frames.

So, when you have a device connected via wire -- a printer connected via an Ethernet cable, for instance, it is sending regular Ethernet packets. The wireless router then has to translate the packets into SNAP format. In reverse, it has to change SNAP packets back into regular Ethernet packets.

The problem, as they say, is a loss in translation. Some SNAP packets need to be specially handled, or else they will end up mangled and unable to be transferred. Some wireless hardware has problems with this translation process, causing the inability to access wired AppleTalk devices over the wireless network.

If you already have a third-party wireless router that doesn't seem to support AppleTalk, there's still hope for accessing the device(s) through IP access.

For printers (the most commonly accessed AppleTalk devices), determine your device's IP address (check the owner's manual for information on how to do so -- usually you can print out a test page by holding a specific button that will tell you the IP address, or you can go to your routers configuration page and look for a way to list connected devices) then use IP printing. This can be accomplished through the following process: