Change Default Network Name (ens33) to eth0 on Debian 10 / Debian 9

Debian 10 / Debian 9 uses a consistent and predictable device name for network interfaces. This predictable device naming helps us to locate network interfaces where it is connected like whether it is attached to onboard or external.

If you ever interested in changing interface name to eth0, then this is the tutorial for you.

As you can see in the below output of ip a command, my Debian system is having a network adapter called enp0s3.

You can confirm that the Ethernet device got renamed during the system boot by using the dmesg command.

sudo dmesg | grep -i eth  ->  enp0s3: renamed from eth0

Disable Consistent Interface Device Naming
To regain the ethX back, edit the grub file.  
Look for GRUB_CMDLINE_LINUX line and add net.ifnames=0 biosdevname=0.

From:
GRUB_CMDLINE_LINUX=""

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

Generate a new grub configuration file using the grub-mkconfig command.

sudo grub-mkconfig -o /boot/grub/grub.cfg
Update Network Interface Configurations
Network Manager
If your system uses NetworkManager for network configuration, then you do not have to modify any settings. You can go ahead and reboot the system.
sudo reboot
Interfaces File
Edit the interface file and change the name of the network device so that you will have a DHCP/static IP address for ethX.

DHCP
If your machine is on a DHCP network, then,
sudo vi /etc/network/interfaces
Update below lines in interface files so that the network card can get an IP address from the DHCP server.

FROM:
auto ens33
iface ens33 inet dhcp
TO:

auto eth0
iface eth0 inet dhcp

source: 
https://www.itzgeek.com/how-tos/linux/debian/change-default-network-name-ens33-to-old-eth0-on-debian-9.html