Fail2ban

Installation

Debian / Ubuntu

# apt-get install fail2ban

Configuration

To be secure on updates put your personal settings in the *.local files. This will protect them from overwriting through update procedures.

paths-overrides.local

I have date parts in my logfiles so the defaults from fail2ban would fail to find the logs.

# exim -bP log_file_path
log_file_path = /var/log/exim/%slog-%D

# doveadm log find
Looking for log files from /var/log
Debug: /var/log/dovecot/dovecot.debug-20160309
Info: /var/log/dovecot/dovecot.debug-20160309
Warning: /var/log/dovecot/dovecot.log-20160309
Error: /var/log/dovecot/dovecot.log-20160309
Fatal: /var/log/dovecot/dovecot.log-20160309

[DEFAULT]

dovecot_log = /var/log/dovecot/dovecot.log-*

exim_main_log = /var/log/exim/mainlog-*

jail.local

[DEFAULT]
bantime = 3600
#
[sshd]
enabled = true

[exim-spam]
enabled = true

[exim]
enabled = true

[sshd-ddos]
enabled  = true

[dovecot]
enabled  = true

[sieve]
enabled  = true