Check Network Up/Down Link speed
tl;dr
sudo apt install -y speedtest-cli
speedtest
Ubuntu 18.04
sudo apt update
sudo apt install -y speedtest-cli
# run
speedtest
Older Linux
wget -O speedtest-cli https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py --no-check-certificate
chmod +x speedtest-cli
# run
./speedtest-cli