$ curl cheat.sh/
# ifup
# Tool used to enable network interfaces.
# More information: <https://manpages.debian.org/latest/ifupdown/ifup.8.html>.

# Enable interface eth0:
ifup eth0

# Enable all the interfaces defined with "auto" in `/etc/network/interfaces`:
ifup -a

$
Follow @igor_chubin cheat.sh tldr