From the dmesg command, you can see that the device got renamed during the system boot.

$ dmesg | grep -i eth

To get an ethX back, edit the grub file.

$ sudo nano /etc/default/grub

Look for “GRUB_CMDLINE_LINUX” and add the following”net.ifnames=0 biosdevname=0“.

From:

GRUB_CMDLINE_LINUX=""

To:

GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"

Generate a new grub file using the following command.

$ sudo grub-mkconfig -o /boot/grub/grub.cfg