centos linux iptables 只开启 ssh 服务

#!/bin/sh
iptables -F
iptables -X
iptables -Z
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT


iptables -A OUTPUT -p tcp --sport 22 -j ACCEPT
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

service iptables save