Once you get iptables working, you’ll probably want iptstate next.
As I understand it — and again, networking is not my strong point — iptstate lets you watch traffic as it crosses iptables, and sort or filter it, like top does. And atop, and powertop, and iotop and. … 😯
I can’t show a whole lot for it, mostly because I don’t have iptables configured right now. The home page has better screenshots of how it looks in action.
I can see where this would be useful, provided it was configured and running properly. And I imagine in a complex network environment, it would be quite impressive to watch.
Of course, I’m a sucker for anything that manages the screen real estate and flashes a little color. 🙄