“#8: Know how to configure an IP address manually
“Yes, there are GUI tools for this. And yes, they all work very
well. But as you will eventually find if you administer any
operating system long enough, it’s never bad to have backup tools
to help you do your job. And one of the best backup tools for Linux
networking is the ifconfig command. Not only will this command
return to you (with no arguments) your network card information, it
will also allow you to configure your network card manually.”