So, sometimes my MBP is in a henge dock which has an Ethernet cable. Sometimes it's not. So I have both Ethernet and wifi connections defined. If both of them come up right around the same time, the system sometimes announces that my name (foo.local) is already in use, so it's renaming itself to "foo2.local". And then a while later, I plug it in, and it announces that "foo2.local" is already in use, so it's renaming itself to "foo3.local". And so on. What I really want is, if the Ethernet comes up, don't bring up wifi at all. And if the Ethernet doesn't come up, bring up wifi. But I can't see an obvious way to do this. I don't want to manually pick locations; I'd rather put up with the mild annoyances of having both active than have to remember to pick locations when the Ethernet is hooked up. EDIT: http://hints.macworld.com/article.php?story=20100927161027611 Someone proposed a launchd-based solution for this, with a script that checks the state of the interfaces. Clever!