There are a handful of tools you never know you missed, unless someone shows them to you. And MTR is clearly one of them.
But what is it doing?
Imagine you are on an unstable internet connection. The first thing you usually would fire up is ping to check if the internet is working. To test if the problem is something in your local network, you would start traceroute as a second command.
Why not combing both onto one little screen that constantly refreshes?
Like this:
Simple, elegant, and all information you need to check the basic network connection.
Install it via brew install mtr on your Mac or aptitude install mtr on your Debian.