iptables 端口安全脚本

iptables 端口安全脚本，适合小白使用，注意端口访问配置哦 自己改

1. #!/bin/bash
   
2. PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
   
3. export PATH
   
4. function support_distro(){
   
5. if [ -z "`egrep -i "centos" /etc/issue`" ];then
   
6. echo "Sorry,iptables script only support centos system now."
   
7. exit 1
   
8. fi
   
9. }
   
10. support_distro
    
11. echo "============================iptables configure============================================"
    
12. # Only support CentOS system
    
13. # 获取SSH端口
    
14. if grep "^Port" /etc/ssh/sshd_config>/dev/null;then
    
15. sshdport=`grep "^Port" /etc/ssh/sshd_config | sed "s/Port\s//g" `
    
16. else
    
17. sshdport=22
    
18. fi
    
19. # 获取DNS服务器IP
    
20. if [ -s /etc/resolv.conf ];then
    
21. nameserver1=`cat /etc/resolv.conf |grep nameserver |awk 'NR==1{print $2 }'`
    
22. nameserver2=`cat /etc/resolv.conf |grep nameserver |awk 'NR==2{print $2 }'`
    
23. fi
    
24. IPT="/sbin/iptables"
    
25. # 删除已有规则
    
26. $IPT --delete-chain
    
27. $IPT --flush
    
28. # 禁止进,允许出,允许回环网卡
    
29. $IPT -P INPUT DROP   
    
30. $IPT -P FORWARD DROP
    
31. $IPT -P OUTPUT ACCEPT
    
32. $IPT -A INPUT -i lo -j ACCEPT
    
33. # 允许已建立的或相关连接的通行
    
34. $IPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
    
35. $IPT -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
    
36. # 限制80端口单个IP的最大连接数为10
    
37. $IPT -I INPUT -p tcp --dport 80 -m connlimit --connlimit-above 10 -j DROP
    
38. # 允许80(HTTP)/873(RSYNC)/443(HTTPS)/20,21(FTP)/25(SMTP)端口的连接
    
39. $IPT -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
    
40. $IPT -A INPUT -p tcp -m tcp --dport 873 -j ACCEPT
    
41. $IPT -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
    
42. $IPT -A INPUT -p tcp -m tcp --dport 139 -j ACCEPT
    
43. $IPT -A INPUT -p tcp -m tcp --dport 445 -j ACCEPT
    
44. $IPT -A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
    
45. # 允许SSH端口的连接,脚本自动侦测目前的SSH端口,否则默认为22端口
    
46. $IPT -A INPUT -p tcp -m tcp --dport $sshdport -j ACCEPT
    
47. # 允许ping
    
48. $IPT -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
    
49. $IPT -A INPUT -p icmp -m icmp --icmp-type 11 -j ACCEPT
    
50. # 允许DNS
    
51. [ ! -z "$nameserver1" ] && $IPT -A OUTPUT -p udp -m udp -d $nameserver1 --dport 53 -j ACCEPT
    
52. [ ! -z "$nameserver2" ] && $IPT -A OUTPUT -p udp -m udp -d $nameserver2 --dport 53 -j ACCEPT
    
53. # 保存规则并重启IPTABLES
    
54. service iptables save
    
55. service iptables restart
    
56. echo "============================iptables configure completed============================================"
    

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