Hello all, I am starting to define the ruleset for iptables... I am open to recommendations, is my intention to begin in this way (please, guide me if this is or not recommended, I am in the beautifull learning curve xD) Code: *filter -A INPUT -p all --dport 1:65535 -j DROP -A INPUT -p tcp -s 127.0.0.1/32 --dport 3306 -j ACCEPT -A INPUT -p udp -s 127.0.0.1/32 --dport 3306 -j ACCEPT -A INPUT -p tcp -s $webip/32 --dport 3306 -j ACCEPT -A INPUT -p udp -s $webip/32 --dport 3306 -j ACCEPT -A INPUT -p tcp -s $mailip/32 --dport 3306 -j ACCEPT -A INPUT -p udp -s $mailip/32 --dport 3306 -j ACCEPT -A INPUT -p tcp -s $dns1ip/32 --dport 3306 -j ACCEPT -A INPUT -p udp -s $dns1ip/32 --dport 3306 -j ACCEPT -A INPUT -p tcp -s $dns2ip/32 --dport 3306 -j ACCEPT -A INPUT -p udp -s $dns2ip/32 --dport 3306 -j ACCEPT .... ----- other rules to ACCEPT traffic for other ports COMMIT Thank you very much.- Edit: ok, bad idea to begin with DROP for all ports xD. The correct way I assume is to Allow first everything I want, and use the first line in the code as the last line xD If someone could give about hidding things to have in count, it is welcome.