iptables服務先關閉

iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
iptables -t nat -P PREROUTING DROP
iptables -t nat -P POSTROUTING DROP
iptables -t nat -P OUTPUT DROP
再依你的需求一條一條的加進你的rule,一邊加邊測試