iptables

Show rule with line number:

iptables -L –line-numbers

DROP RULE:

sudo iptables -D INPUT number

Accept port with special IP: Chèn lên đầu

sudo iptables -I INPUT 1 -p tcp –dport 80 -s {IP} -j ACCEPT

DROP ALL A PORT:

sudo iptables -I INPUT 7 -p tcp –dport 22 -j DROP

DROP

SAVE: sudo service iptables save