Too many users have been facing Ethernet does not work in El Capitan after upgrading to Mac OS X 10.11. How to fix completely?
- Firstly, remove and delete all available network interfaces in System Preferences > Network
- Next, delete and remove completely NetworkInterfaces.plist (Found in /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist) and the preferences.plist (Found in /Library/Preferences/SystemConfiguration/preferences.plist).
- Restart your Mac
- After Reboot go to System Preferences > Network and add all network interfaces (wi-fi Ethernet and other).