DenyHosts是Python语言写的一个程序，它会分析sshd的日志文件（/var/log/secure），当发现重 复的攻击时就会记录IP到/etc/hosts.deny文件，从而达到自动屏IP的功能
DenyHosts官方网站 http://denyhosts.sourceforge.net
下载页面 http://sourceforge.net/projects/denyhosts/files/
tar -xzf DenyHosts-2.6.tar.gz cd DenyHosts-2.6 python setup.py install cd /usr/share/denyhosts/ #安装目录 cp denyhosts.cfg-dist denyhosts.cfg
vim denyhosts.cfg
############ THESE SETTINGS ARE REQUIRED ############ SECURE_LOG = /var/log/secure #系统的ssh日志，centos默认是这个文件 HOSTS_DENY = /etc/hosts.deny #被阻止ip的文档 PURGE_DENY = 2d #阻止时间 BLOCK_SERVICE = sshd DENY_THRESHOLD_INVALID = 5 #允许无效用户登录失败的次数 DENY_THRESHOLD_VALID = 10 #允许普通用户登录失败的次数 DENY_THRESHOLD_ROOT = 3 #允许root登录失败的次数 DENY_THRESHOLD_RESTRICTED = 3 #设定 deny host 写入到该资料夹 WORK_DIR = /usr/share/denyhosts/data #将deny的host或ip纪录到Work_dir中 SUSPICIOUS_LOGIN_REPORT_ALLOWED_HOSTS=YES HOSTNAME_LOOKUP=YES #是否做域名反解 LOCK_FILE = /var/lock/subsys/denyhosts ############ THESE SETTINGS ARE OPTIONAL ############ ADMIN_EMAIL = your_mail@163.com SMTP_HOST = localhost SMTP_PORT = 25 SMTP_FROM = DenyHosts <nobody@localhost> SMTP_SUBJECT = DenyHosts Report AGE_RESET_VALID=5d AGE_RESET_ROOT=25d AGE_RESET_RESTRICTED=25d AGE_RESET_INVALID=10d ######### THESE SETTINGS ARE SPECIFIC TO DAEMON MODE ########## DAEMON_LOG = /var/log/denyhosts #denyhosts自己的日志 DAEMON_SLEEP = 30s DAEMON_PURGE = 1h
cp daemon-control-dist daemon-control chown root daemon-control chmod 700 daemon-control ./daemon-control start ln -s /usr/share/denyhosts/daemon-control /etc/init.d/denyhosts chkconfig --level 2345 denyhosts on
#重启服务以及进程 service denyhosts restart
sent DenyHosts SIGTERM starting DenyHosts: /usr/bin/env python /usr/bin/denyhosts.py --daemon --config=/usr/share/denyhosts/denyhosts.cfg
cat /etc/hosts.deny #查看阻止的ip 记录
如果取消这个ip的限制，则在/etc/hosts.deny 删除ip信息
