A newbie Mac networking question: I have my Macbook connected as a HTPC with an ethernet cable running to my AEBS. Since this is a laptop and also my "general" computer, I "dock" and undock the Macbook fairly often. I leave Airport on for those times when I have to undock and bring the Macbook outside or wherever.

The problem is: when I plug back into the Ethernet cable and leave Airport on, Macbook decides to use the slower Wi-Fi connection instead of Ethernet. In order to enjoy the faster wired connection, I have to manually turn Airport off. Is there a "preference setting" somewhere where I can tell Macbook to always use Ethernet unless it is unavailable?

Go into System Preferences > Network and drag Built-in ethernet up to the top spot, it'll try that first, then look to Airport second. As a test, leave that preference open while you're on wireless only--then plug in your ethernet cable--you should see it go active and move up to the top spot, moving Airport down. (One caveat--if you happen to be screen sharing at that moment or connected to another Mac volume, your Mac will stay connected over the wireless connection even after you plug the ethernet in. That won't normally be the case, but I'm just saying...)

Brilliant. Thanks.

In Leopard 10.5 it's a bit trickier. (and perhaps even LESS INTUITIVE) than it was in 10.4's Network Prefs Pane. You can't just drag to reprioritize network interfaces. Now you have to click the tiny unobtrusive little 'gear' icon to 'Set Service Order' and yet-another dialog pops up. But Apple's getting smarter - at least there it clearly states "Drag Services To Change Order".

The only thing they forgot was "PLACE A SERVICE ORDER: Please click the Dial-Up Telephone icon to place a call to have a Mac technician dispatched to figure out how to configure our convoluted Network settings FOR you!"

This is a pet peeve of mine: Between Network setting and Printer Setup - Apple keeps changing it with each major release. Ya'd think they'da had this figured out once and for all by 10.2.8, huh?

DocMac, you are right. I had to click the gear button. After trying unsuccessfully to drag/drop as chiefklc said, I decided to see what the "gear" was; and got lucky.