insmod ip_conntrack_ftp
添加FTP跟踪模块
FTP服务器如果是被动FTP则如下:
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -A INPUT -p tcp --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp --sport 21 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --dport 1024: -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp --dport 1024: -m state --state ESTABLISHED -j ACCEPT