Debian安装fail2ban来防止扫描

vps的root密码不要设置的太简单，这样很容易被攻破，你可以安装如下软件来降低vps被攻破的机会。

输入如下命令：

apt-get install fail2ban

提示如下表示安装完成：

root@241541:/# ~# apt-get install fail2ban
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  python-pyinotify
Suggested packages:
  python-gamin python-pyinotify-doc
The following NEW packages will be installed:
  fail2ban python-pyinotify
0 upgraded, 2 newly installed, 0 to remove and 62 not upgraded.
Need to get 154 kB of archives.
After this operation, 763 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu/ trusty/universe fail2ban all 0.8.11-1 [129 kB]
Get:2 http://archive.ubuntu.com/ubuntu/ trusty/main python-pyinotify all 0.9.4-1build1 [24.5 kB]
Fetched 154 kB in 0s (213 kB/s)
Selecting previously unselected package fail2ban.
(Reading database ... 28959 files and directories currently installed.)
Preparing to unpack .../fail2ban_0.8.11-1_all.deb ...
Unpacking fail2ban (0.8.11-1) ...
Selecting previously unselected package python-pyinotify.
Preparing to unpack .../python-pyinotify_0.9.4-1build1_all.deb ...
Unpacking python-pyinotify (0.9.4-1build1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
fopen: Permission denied
Setting up fail2ban (0.8.11-1) ...
 * Starting authentication failure monitor fail2ban                                                                                                                       [ OK ]
Setting up python-pyinotify (0.9.4-1build1) ...

这样如果用户5次密码输入错误，将会自动将其IP加到黑名单，禁止登录10分钟，10分钟后才可以再登录。