shell脚本设置防止暴力破解ssh

shell脚本设置访问控制，多次失败登录即封掉IP，防止暴力破解ssh

当发现某一台主机向服务器进行SSH远程管理，在10分钟内输错密码3次，使用firewalld进行响应, 禁止此IP再次连接，6个小时候后再次允许连接。

一、系统：Centos7.1 64位

二、方法：读取/var/log/secure，查找关键字 Failed

Jan  4 16:29:01 centos7 sshd[1718]: Failed password for root from 192.168.120.1 port 2171 ssh2
Jan  4 16:29:02 centos7 sshd[1718]: pam_succeed_if(sshd:auth): requirement "uid >= 1000" not met by user "root"
Jan  4 16:29:04 centos7 sshd[1718]: Failed password for root from 192.168.120.1 port 2171 ssh2
Jan  4 16:29:06 centos7 sshd[1718]: error: Received disconnect from 192.168.120.1 port 2171:0:  [preauth]
Jan  4 16:45:53 centos7 sshd[1758]: Failed password for root from 192.168.120.134 port 40026 ssh2