Realtime Bandwidth monitoring tools on Ubuntu
Speed tests are nice for a simple look at whether or not you’re getting the speed you pay for from your ISP. However, if you want a detailed look at what’s going in and our of your system, you need to be monitoring the actual ethernet adapter. Ubuntu lets you do that with a couple of different commands.
I prefer iftop. You have to install it though as it is not a core system functionality.
You can see that every connection that is going through the adapter is listed out with details about how much bandwidth it’s taking. It shows both outbound and inbound. At the bottom of the screen, if you leave iftop running, it will also give you a cumulative total of the outbound and inbound traffic.