Slow Down Ethernet

# Switch Ethernet back to 100 MB...

# Install ethtool
sudo apt-get install ethtool

# Check Ethernet Speed:
sudo ethtool eth0

# Set Ethernet to 100 (manually)
sudo ethtool -s eth0 speed 100 duplex full autoneg on

Note: Slowing down the Ethernet will not stick... thus we need to turn it off via systemd... So...

# Set Ethernet to 100 (automatically)

Step1 - Create a bash script "slowethernet.sh" for adjusting the Ethernet speed
sudo nano slowethernet.sh
===CONTENTS=========
#!/bin/bash
/sbin/ethtool -s eth0 speed 100 duplex full autoneg on
====================

Step2 - Make the script files executable
sudo chmod 744 ~/slowethernet.sh

Note: At this point you can test the script.
eg. sudo ~/slowethernet.sh

Step3 - Create a Service Unit file
sudo nano /etc/systemd/system/slowethernet.service

Add the following contents to the service file:
=====================
[Unit]
Description=SlowEthernet
After=network-online.target
Wants=network-online.target

[Service]
ExecStart=/home/osmc/slowethernet.sh

[Install]
WantedBy=default.target
=====================

sudo chmod 664 /etc/systemd/system/slowethernet.service
sudo systemctl daemon-reload

To Enable Run at Boot:
sudo systemctl enable slowethernet.service

To Start it Manually:
sudo systemctl start slowethernet.service

To Stop it Manually: 
sudo systemctl stop slowethernet.service