OSX重置en0, en1, en2等引起的登陆问题.

有时网卡的顺序乱了, 网卡不是默认的en0就会引起很多问题, 例如不能登陆App store, iCloud会出现问题. 参考了苹果官方的文档, 很简单就解决了.
http://support.apple.com/kb/TS3925?viewlocale=en_US&locale=en_US
进去/Library/Preferences/SystemConfiguration, 删除networkinterfaces.plist文件, 然后重启电脑进去设置网络添加新的资料就OK.

1. Click the Finder icon in the Dock.
2. Choose Go to Folder from the Go menu.
3. Type /Library/Preferences/SystemConfiguration
4. Copy the file networkinterfaces.plist to the desktop (to make a precautionary backup).
5. Delete the file “networkinterfaces.plist.” from SystemConfiguration.
6. Restart your Mac.
7. Create new location in Network preferences, in System Preferences.