Days ago I learnt ipfw firewall under FreeBSD. I found its rule is very simple. Its syntax is very similar to our speakings, we can understand it easily.
Of course, a lazy man like me will not learn it deeply. I just write my own rule after I learnt the syntax.
This configuration could be used at home, I open tcp, udp, ssh and e-mail ports. It is not very perfect, and there should be space for improvement. Please give me some advice.