Provided by: fail2ban_0.8.11-1_all
jail.conf - configuration for the fail2ban server
fail2ban.conf fail2ban.d/*.conf fail2ban.d/*.local jail.conf / jail.local action.d/*.conf action.d/*.local filter.d/*.conf filter.d/*.local
Fail2ban has three configuration file types. Action files are the commands for banning and unbanning of IP address, Filter files tell fail2ban how to detect authentication failures, and Jail configurations combine filters with actions into jails. There are *.conf files that are distributed by fail2ban and *.local file that contain user customizations. It is recommended that *.conf files should remain unchanged. If needed, customizations should be provided in *.local files. For instance, if you would like to customize the [ssh-iptables-ipset] jail, create a jail.local to extend jail.conf (the configuration for the fail2ban server). The jail.local file will be the following if you only need to enable it: jail.local [ssh-iptables-ipset] enabled = true Override only the settings you need to change and the rest of the configuration will come from the corresponding *.conf file. *.d/ In addition to .local, for any .conf file there can be a corresponding .d/ directory to contain additional .conf files that will be read after the appropriate .local file. Last parsed file will take precidence over identical entries, parsed alphabetically, e.g. jail.d/01_enable.conf - to enable a specific jail jail.d/02_custom_port.conf - containing specific configuration entry to change the port of the jail specified in the configuration fail2ban.d/01_custom_log.conf - containing specific configuration entry to use a different log path. The order jail configuration is parsed is: jail.conf , jail.d/*.conf (in alphabetical order), jail.local, followed by jail.d/*.local (in alphabetical order). Likewise for fail2ban configuration. Comments: use '#' for comment lines and ';' (following a space) for inline comments
The following options are applicable to all jails. Their meaning is described in the default jail.conf file. ignoreip bantime findtime maxretry backend usedns
Action files specify which commands are executed to ban and unban an IP address. They are located under /etc/fail2ban/action.d. Like with jail.conf files, if you desire local changes create an [actionname].local file in the /etc/fail2ban/action.d directory and override the required settings. Action files are ini files that have two sections, Definition and Init . The [Init] section allows for action-specific settings. In jail.conf/jail.local these can be overwritten for a particular jail as options to the jail. The following commands can be present in the [Definition] section. actionstart command(s) executed when the jail starts. actionstop command(s) executed when the jail stops. actioncheck the command ran before any other action. It aims to verify if the environment is still ok. actionban command(s) that bans the IP address after maxretry log lines matches within last findtime seconds. actionunban command(s) that unbans the IP address after bantime. Commands specified in the [Definition] section are executed through a system shell so shell redirection and process control is allowed. The commands should return 0, otherwise error would be logged. Moreover if actioncheck exits with non-0 status, it is taken as indication that firewall status has changed and fail2ban needs to reinitialize itself (i.e. issue actionstop and actionstart commands). Tags are enclosed in <>. All the elements of [Init] are tags that are replaced in all action commands. Tags can be added by the fail2ban-client using the setctag command. <br> is a tag that is always a new line (\n). More than a single command is allowed to be specified. Each command needs to be on a separate line and indented with whitespaces without blank lines. The following example defines two commands to be executed. actionban = iptables -I fail2ban-<name> --source <ip> -j DROP echo ip=<ip>, match=<match>, time=<time> >> /var/log/fail2ban.log Action Tags The following tags are substituted in the actionban, actionunban and actioncheck (when called before actionban/actionunban) commands. ip An IPv4 ip address to be banned. e.g. 192.168.0.2 failures The number of times the failure occurred in the log file. e.g. 3 time The unix time of the ban. e.g. 1357508484 matches The concatenated string of the log file lines of the matches that generated the ban. Many characters interpreted by shell get escaped.
Filter definitions are those in /etc/fail2ban/filter.d/*.conf and filter.d/*.local. These are used to identify failed authentication attempts in logs and to extract the host IP address (or hostname if usedns is true). Like action files, filter files are ini files. The main section is the [Definition] section. There are two filter definitions used in the [Definition] section: failregex is the regex (regular expression) that will match failed attempts. The tag <HOST> is used as part of the regex and is itself a regex for IPv4 addresses and hostnames. fail2ban will work out which one of these it actually is. ignoreregex is the regex to identify log entries that should be ignored by fail2ban, even if they match failregex. Using Python "string interpolation" mechanisms, other definitions are allowed and can later be used within other definitions as %(defnname)s. For example. baduseragents = IE|wget failregex = useragent=%(baduseragents)s Filters can also have a section called [INCLUDES]. This is used to read other configuration files. before indicates that this file is read before the [Definition] section. after indicates that this file is read after the [Definition] section.
Fail2ban was originally written by Cyril Jaquier <email@example.com>. At the moment it is maintained and further developed by Yaroslav O. Halchenko <firstname.lastname@example.org> and a number of contributors. See THANKS file shipped with Fail2Ban for a full list. Manual page written by Daniel Black and Yaroslav Halchenko.
Report bugs to https://github.com/fail2ban/fail2ban/issues
Copyright © 2013 Daniel Black Copyright of modifications held by their respective authors. Licensed under the GNU General Public License v2 (GPL).