这是Linux中iptables的一个很好的起点吗？

我是iptables的新手,我一直在尝试组建一个防火墙,其目的是保护Web服务器.以下规则是我到目前为止所组建的规则,我想听听这些规则是否有意义 – 而且我已经遗漏了任何必要的东西？

除了端口80,我还需要为外部连接打开端口3306(mysql)和22(ssh).

任何反馈都非常感谢！

#!/bin/sh

# Clear all existing rules.
iptables -F

# ACCEPT connections for loopback network connection,127.0.0.1.
iptables -A INPUT -i lo -j ACCEPT

# ALLOW established traffic
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

# DROP packets that are NEW but does not have the SYN but set.
iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP

# DROP fragmented packets,as there is no way to tell the source and destination ports of such a packet.
iptables -A INPUT -f -j DROP

# DROP packets with all tcp flags set (XMAS packets).
iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP

# DROP packets with no tcp flags set (NULL packets).
iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP

# ALLOW ssh traffic (and prevent against DoS attacks)
iptables -A INPUT -p tcp --dport ssh -m limit --limit 1/s  -j ACCEPT

# ALLOW http traffic (and prevent against DoS attacks)
iptables -A INPUT -p tcp --dport http -m limit --limit 5/s -j ACCEPT

# ALLOW MysqL traffic (and prevent against DoS attacks)
iptables -A INPUT -p tcp --dport MysqL -m limit --limit 25/s -j ACCEPT

# DROP any other traffic.
iptables -A INPUT -j DROP

解决方法

试试shorewall,提供开箱即用的合理防火墙.从网络启用对所需服务的访问.有一个,两个和三个接口的示例规则集.文档很好,并且积极维护.

我希望您能够限制哪些地址可以轻松访问MysqL.除非您最近探测过另一个端口,否则您还可以在端口关闭的情况下使用端口敲门来保护SSH.