Odroid H2 rtl_nic

Warnings in dmesg for Odroid H2 when booting:

r8169 0000:02:00.0: firmware: failed to load rtl_nic/rtl8168g-2.fw (-2)
r8169 0000:02:00.0: Direct firmware load for rtl_nic/rtl8168g-2.fw failed with error -2
r8169 0000:03:00.0: firmware: failed to load rtl_nic/rtl8168g-2.fw (-2)
r8169 0000:03:00.0: Direct firmware load for rtl_nic/rtl8168g-2.fw failed with error -2

Make sure the following is in

/etc/apt/sources.list

deb http://ftp.uk.debian.org/debian/ stretch non-free
deb-src http://ftp.uk.debian.org/debian/ stretch non-free

Then do

sudo apt-get update
sudo apt-get install firmware-realtek

and reboot and the warning goes away