ubuntu中防火墙iptables配置

特别说明：此文章彻底转载于http://www.javashuo.com/article/p-pgfybifv-bh.html

1.查看系统是否安装防火墙

root@localhost:/usr# which iptables /sbin/iptables root@localhost:/usr# whereis iptables iptables: /sbin/iptables /etc/iptables /usr/share/iptables /usr/share/man/man8/iptables.8.gz 

若是是这样的信息，那么代表iptables就是安装了的。
若是没有安装，那么使用sudo apt-get install iptables 安装。

2.查看防火墙的配置信息

配置好了的，是这个样子。

root@localhost:/usr# sudo iptables -L Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT tcp -- anywhere anywhere state NEW tcp dpt: 22 ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:http ACCEPT icmp -- anywhere anywhere limit: avg 100/sec burst 100 ACCEPT icmp -- anywhere anywhere limit: avg 1/sec burst 10 syn-flood tcp -- anywhere anywhere tcp flags:FIN,SYN,RST,ACK/SYN REJECT all -- anywhere anywhere reject-with icmp-host-prohibited Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain syn-flood (1 references) target prot opt source destination RETURN tcp -- anywhere anywhere limit: avg 3/sec burst 6 REJECT all -- anywhere anywhere reject-with icmp-port-unreachable 

3.新建规则文件

mkdir /etc/iptables #先新建目录，自己无此目录 vim /etc/iptables/rules.v4 

/etc/iptables/rules.v4 中的内容是

*filter
:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:syn-flood - [0:0]
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT
-A INPUT -p icmp -m limit --limit 100/sec --limit-burst 100 -j ACCEPT -A INPUT -p icmp -m limit --limit 1/s --limit-burst 10 -j ACCEPT -A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -j syn-flood -A INPUT -j REJECT --reject-with icmp-host-prohibited -A syn-flood -p tcp -m limit --limit 3/sec --limit-burst 6 -j RETURN -A syn-flood -j REJECT --reject-with icmp-port-unreachable COMMIT 

4.使防火墙生效

iptables-restore < /etc/iptables/rules.v4 

5.建立文件，添加如下内容，使防火墙开机启动

vim /etc/network/if-pre-up.d/iptables 

#!/bin/bash iptables-restore < /etc/iptables/rules.v4 

6.添加执行权限

chmod +x /etc/network/if-pre-up.d/iptables 

7.查看规则是否生效

iptables -L -n

Ubuntu中没有直接中止关闭iptables的命令，像service iptables stop这类命令，是centos才有的。关闭的话，能够暂时开放全部端口做为替代方案

iptables -P INPUT ACCEPT  
iptables -P OUTPUT ACCEPT

还能够参考https://blog.csdn.net/langsim/article/details/42644451

做者：yangyangrenren 连接：https://www.jianshu.com/p/6fe337cedbcb 来源：简书 简书著做权归做者全部，任何形式的转载都请联系做者得到受权并注明出处。