Fail2ban
Fail2ban scans log files (e.g. /var/log/apache/error_log) and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc. Generally Fail2Ban then used to update firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email, or ejecting CD-ROM tray) could also be configured. Out of the box Fail2Ban comes with filters for various services (apache, curier, ssh, etc). For more info refer to the official web site
How to install Fail2ban. Enable Epel repository first:wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm
Enable the remi repository.
Open the file /etc/yum.repos.d/remi.repo and set enable=1 in remi section of the file.name=Les RPM de remi pour Enterprise Linux $releasever - $basearch
#baseurl=http://rpms.famillecollet.com/enterprise/$releasever/remi/$basearch/
mirrorlist=http://rpms.famillecollet.com/enterprise/$releasever/remi/mirror
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi
failovermethod=priority
Now install Fail2ban:
yum install fail2ban
Set Fail2ban to start at boot
chkconfig fail2ban on
Copy config file to keep the original backup.
cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local
Now we have a working config file /etc/fail2ban/jail.local, configure it according to your needs.
Start serviceservice fail2ban start
Now you have working Fail2ban server. To display banned hosts, enter:
iptables -L
To unlock IP, enter
iptables -D fail2ban-ssh 1
