I've been using this module in a project, and users have reported problems on various platforms -- the problems all boil down to my use of macaddress, but only when their machines are offline.

I haven't been able to reproduce the issue personally on OSX, but on Windows 8.1 I see the problem.

mac.all(function (err, all) {
    for (var prop in all) {
        console.log(all[ prop ].mac); //will always be blank output when offline
    }
});

To be clear, my Windows 8.1 machine does not have WIFI -- it only uses a hard ethernet connection. Removing that hard line is when I see the issue.