Ubuntu15 and below's NIC naming problem

http://askubuntu.com/questions/689070/network-interface-name-changes-after-update-to-15-10-udev-changes

After Ubuntu 15.10 (Wily Werewolf) the NIC naming rule are changed.

 If you want to keep the naming rule as ethX You need to do following steps.

1.  Edit /etc/default/grub 
2.  GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0" 
3. Run command "update-grub" as root 

Final, reboot the machine, the NIC name will use ethX