<yambe:breadcrumb>CentOS_7.x_Security_Tools|CentOS 7.x Security Tools</yambe:breadcrumb>

CentOS 7.x fail2ban

To configure fail2ban on CentOS 7.x use:

Install fail2ban using

yum -y install epel-release
yum -y install fail2ban

Create a local copy of configuration files for local modifications. We should not modify .conf files directly as they would get overwritten during package upgrades
```
cp /etc/fail2ban/fail2ban.conf /etc/fail2ban/fail2ban.local
cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local
```
Edit /etc/fail2ban/jail.local to set backend to systemd and to also enable jail for sshd
```
...
backend=systemd
...
[sshd]
enabled = true
...
```

Start and enable fail2ban on system boot

systemctl start fail2ban
systemctl enable fail2ban

Ensure that firewalld is enabled as that is required by fail2ban using CentOS 7.x Basic firewalld configuration
Verify that fail2ban is running with at least 1 jail and that jail has one or more blocked IPs
```
fail2ban-client status
fail2ban-client status sshd
```

There is also older article on fail2ban at Fail2ban

In case of email server using postfix and dovecot add

   enabled=true

under dovecot and posfix-sasl also. This would then create three jails including sshd.

Refer:

Anonymous