1. 程式人生 > >常用linux iptables 25個規則

常用linux iptables 25個規則

# 1. 刪除所有現有規則


iptables -F


# 2. 設定預設的 chain 策略


iptables -P INPUT DROP

iptables -P FORWARD DROP

iptables -P OUTPUT DROP


# 3. 阻止某個特定的 IP 地址


#BLOCK_THIS_IP="x.x.x.x"

#iptables -A INPUT -s "$BLOCK_THIS_IP" -j DRO


# 4. 允許全部進來的(incoming)SSH


iptables -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A OUTPUT -o eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT


# 5. 只允許某個特定網路進來的 SSH


#iptables -A INPUT -i eth0 -p tcp -s 192.168.200.0/24 --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT


# 6. 允許進來的(incoming)HTTP


iptables -A INPUT -i eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A OUTPUT -o eth0 -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT


# 7. 多埠(允許進來的 SSH、HTTP 和 HTTPS)


iptables -A INPUT -i eth0 -p tcp -m multiport --dports 22,80,443 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A OUTPUT -o eth0 -p tcp -m multiport --sports 22,80,443 -m state --state ESTABLISHED -j ACCEPT


# 8. 允許出去的(outgoing)SSH


iptables -A OUTPUT -o eth0 -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A INPUT -i eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT


# 9. 允許外出的(outgoing)SSH,但僅訪問某個特定的網路


#iptables -A OUTPUT -o eth0 -p tcp -d 192.168.101.0/24 --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A INPUT -i eth0 -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT


# 10. 允許外出的(outgoing) HTTPS


iptables -A OUTPUT -o eth0 -p tcp --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A INPUT -i eth0 -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT


# 11. 對進來的 HTTPS 流量做負載均衡


#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 0 -j DNAT --to-destination 192.168.1.101:443

#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 1 -j DNAT --to-destination 192.168.1.102:443

#iptables -A PREROUTING -i eth0 -p tcp --dport 443 -m state --state NEW -m nth --counter 0 --every 3 --packet 2 -j DNAT --to-destination 192.168.1.103:443


# 12. 從內部向外部 Ping


iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT

iptables -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT


# 13. 從外部向內部 Ping


iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT

iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT


# 14. 允許環回(loopback)訪問


iptables -A INPUT -i lo -j ACCEPT

iptables -A OUTPUT -o lo -j ACCEPT


# 15. 允許 packets 從內網訪問外網


# if eth1 is connected to external network (internet)

# if eth0 is connected to internal network (192.168.1.x)

iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT


# 16. 允許外出的  DNS


iptables -A OUTPUT -p udp -o eth0 --dport 53 -j ACCEPT

iptables -A INPUT -p udp -i eth0 --sport 53 -j ACCEPT


# 17. 允許 NIS 連線


# rpcinfo -p | grep ypbind ; This port is 853 and 850

#iptables -A INPUT -p tcp --dport 111 -j ACCEPT

#iptables -A INPUT -p udp --dport 111 -j ACCEPT

#iptables -A INPUT -p tcp --dport 853 -j ACCEPT

#iptables -A INPUT -p udp --dport 853 -j ACCEPT

#iptables -A INPUT -p tcp --dport 850 -j ACCEPT

#iptables -A INPUT -p udp --dport 850 -j ACCEPT


# 18. 允許某個特定網路 rsync 進入本機


#iptables -A INPUT -i eth0 -p tcp -s 192.168.101.0/24 --dport 873 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 873 -m state --state ESTABLISHED -j ACCEPT


# 19. 僅允許來自某個特定網路的 MySQL 的連結


#iptables -A INPUT -i eth0 -p tcp -s 192.168.200.0/24 --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 3306 -m state --state ESTABLISHED -j ACCEPT


# 20. 允許 Sendmail 或 Postfix


iptables -A INPUT -i eth0 -p tcp --dport 25 -m state --state NEW,ESTABLISHED -j ACCEPT

iptables -A OUTPUT -o eth0 -p tcp --sport 25 -m state --state ESTABLISHED -j ACCEPT


# 21. 允許 IMAP 和 IMAPS


#iptables -A INPUT -i eth0 -p tcp --dport 143 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 143 -m state --state ESTABLISHED -j ACCEPT

#iptables -A INPUT -i eth0 -p tcp --dport 993 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 993 -m state --state ESTABLISHED -j ACCEPT


# 22. 允許 POP3 和 POP3S


#iptables -A INPUT -i eth0 -p tcp --dport 110 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 110 -m state --state ESTABLISHED -j ACCEPT

#iptables -A INPUT -i eth0 -p tcp --dport 995 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 995 -m state --state ESTABLISHED -j ACCEPT


# 23. 防止 DoS 攻擊


iptables -A INPUT -p tcp --dport 80 -m limit --limit 25/minute --limit-burst 100 -j ACCEPT


# 24. 設定 422 埠轉發到 22 埠


#iptables -t nat -A PREROUTING -p tcp -d 192.168.102.37 --dport 422 -j DNAT --to 192.168.102.37:22

#iptables -A INPUT -i eth0 -p tcp --dport 422 -m state --state NEW,ESTABLISHED -j ACCEPT

#iptables -A OUTPUT -o eth0 -p tcp --sport 422 -m state --state ESTABLISHED -j ACCEPT


# 25. 為丟棄的包做日誌(Log)


iptables -N LOGGING

iptables -A INPUT -j LOGGING

iptables -A LOGGING -m limit --limit 2/min -j LOG --log-prefix "IPTables Packet Dropped: " --log-level 7

iptables -A LOGGING -j DROP