Fail2Ban – intrusion prevention software framework

Last Updated on October 17, 2023

Fail2Ban is a daemon to ban hosts that cause multiple authentication errors. The software scans log files like /var/log/pwdfail pwdfail and bans IP addresses that make too many password failures.

It updates firewall rules to reject the IP address.  These rules can be defined by the user.

Fail2Ban can read multiple log files such as sshd or Apache Web server ones. Fail2Ban comes out-of-the-box ready to read many standard log files, such as those for sshd and Apache, and is easily configured to read any log file of your choosing, for any error you wish.

Features include:

• Python based actions.
• Database support.
• Multi-line parsing in filters.
• Custom date time support for filters.
• Timezone awareness by default.
• Timeout on ban commands.
• Character set awareness in log files.
• Python3+ support.
• Client/Server architecture.
• Multi-threaded.
• Highly configurable using split configuration files
• Gamin/Pyinotify support.
• Parses log files and look for given patterns.
• Executes command(s) when a pattern has been detected for the same IP address for more than X times to ban that address. X can be changed.
• After a given amount of time, execute another command in order to unban the IP address.
• Uses Netfilter/Iptables by default but can also use TCP Wrapper (/etc/hosts.deny) and many other firewalls/actions.
• Handles log files rotation.
• Can handle multiple services at once (sshd, apache, vsftpd, etc).
• Resolves DNS hostname to IP address (use with caution, disable by usedns = no).

Website: github.com/fail2ban/fail2ban
Support:
Developer: Cyril Jaquier, Yaroslav Halchenko, Daniel Black, Steven Hiscocks, Arturo ‘Buanzo’ Busleiman, and others
License: GNU General Public License v2.0

Fail2Ban is written in Python. Learn Python with our recommended free books and free tutorials.

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