Q When I first set up my new MacBook Pro, I connected it by Ethernet cable to my iMac to transfer files. I have since been trying to exchange documents between the Macs using Wi-Fi, but whenever I try to start this up, the MacBook behaves as if it is still looking for the original Ethernet connect, reporting that it cannot find the specified IP address and telling me to connect the network cable. Wi-Fi is selected in the Network pane, and once this issue works through it seems to function fine. How can I stop this initial trouble?

A When Macs with multiple network connections try to hook up to another Mac or device, they do so in the order that the connections are listed in the Network pane in System Preferences.

Now that you want to make mainly wireless connections, you need to make Wi-Fi the first in your MacBook Pro’s list of connections, so that it will try that before it worries about whether there is an Ethernet cable plugged in.

Open the Network pane, then click on the cog tool at the bottom of the list of connections, and select the Set Service Order item in the resulting popup menu. In the drop-down sheet listing the order of connections, drag Wi-Fi to the top of the list, above Ethernet, and click on OK to save. If you are not intending to use Ethernet wired connections much in the future, it can also be good to remove that item from the main Network pane: select Ethernet and click on the – tool at the foot of the list of connections. You can always use the + tool to add it back if you need to in the future.

Updated from the original, which was first published in MacUser volume 26 issue 24, 2010.