raspi-netmon

Create a fresh installation of raspian-lite:

https://www.raspberrypi.org/downloads/raspbian/
dd image to SD-Card and add an empty file ssh to boot folder
boot device add ssh into it (user pi, password raspberry)
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no pi@<ip_of_raspi>
configure device as needed using sudo raspi-config
- Change timezone
- Enable ssh, i2c

Download and execute the installer:

wget -O - https://raw.githubusercontent.com/pl31/raspi-netmon/master/installer/installer.sh | sh

Per default netmon uses a 20x4 display. To use 16x2 execute:

sudo systemctl disable netmon@20x4.service 
sudo systemctl enable netmon@16x2.service

If happy with the result, make SD-Card read-only:

sudo bash -c "$(wget -O - https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/read-only-fs.sh)"