JAIL.CONF(5)						      Fail2Ban Configuration						      JAIL.CONF(5)

NAME

       jail.conf - configuration for the fail2ban server

SYNOPSIS

       fail2ban.conf fail2ban.d/*.conf fail2ban.local fail2ban.d/*.local

       jail.conf jail.d/*.conf jail.local jail.d/*.local

       action.d/*.conf action.d/*.local action.d/*.py

       filter.d/*.conf filter.d/*.local

DESCRIPTION

       Fail2ban has four configuration file types:

       fail2ban.conf
	      Fail2Ban global configuration (such as logging)

       filter.d/*.conf
	      Filters specifying how to detect authentication failures

       action.d/*.conf
	      Actions defining the commands for banning and unbanning of IP address

       jail.conf
	      Jails defining combinations of Filters with Actions.

CONFIGURATION FILES FORMAT

       *.conf  files  are distributed by Fail2Ban.  It is recommended that *.conf files should remain unchanged to ease upgrades.  If needed, cus-
       tomizations should be provided in *.local files.  For example, if you would like to  enable  the  [ssh-iptables-ipset]  jail  specified	in
       jail.conf, create jail.local containing

       jail.local
	      [ssh-iptables-ipset]

	      enabled = true

       In  .local files specify only the settings you would like to change and the rest of the configuration will then come from the corresponding
       .conf file which is parsed first.

       jail.d/ and fail2ban.d/

	      In addition to .local, for jail.conf or fail2ban.conf file there can be a corresponding .d/ directory  containing  additional  .conf
	      files. The order e.g. for jail configuration would be:

	      jail.conf
	      jail.d/*.conf (in alphabetical order)
	      jail.local
	      jail.d/*.local (in alphabetical order).

	      i.e. all .local files are parsed after .conf files in the original configuration file and files under .d directory.  Settings in the
	      file parsed later take precedence over identical entries in previously parsed files.  Files are ordered alphabetically, e.g.

	      fail2ban.d/01_custom_log.conf - to use a different log path
	      jail.d/01_enable.conf - to enable a specific jail
	      jail.d/02_custom_port.conf - to change the port(s) of a jail.

       Configuration files have sections, those specified with [section name], and name = value pairs. For those name items that can accept multi-
       ple  values,  specify  the  values  separated by spaces, or in separate lines space indented at the beginning of the line before the second
       value.

       Configuration files can include other (defining common variables) configuration files, which is often used in  Filters  and  Actions.  Such
       inclusions are defined in a section called [INCLUDES]:

       before indicates that the specified file is to be parsed before the current file.

       after  indicates that the specified file is to be parsed after the current file.

       Using Python "string interpolation" mechanisms, other definitions are allowed and can later be used within other definitions as %(name)s.

       Fail2ban  has  more  advanced syntax (similar python extended interpolation). This extended interpolation is using %(section/parameter)s to
       denote a value from a foreign section.
       Besides cross section interpolation the value of parameter in [DEFAULT] section can be retrieved with %(default/parameter)s.
       Fail2ban supports also another feature named %(known/parameter)s (means last known option with name parameter).	This  interpolation  makes
       possible to extend a stock filter or jail regexp in .local file (opposite to simply set failregex/ignoreregex that overwrites it), e.g.

	      baduseragents = IE|wget|%(my-settings/baduseragents)s
	      failregex = %(known/failregex)s
			  useragent=%(baduseragents)s

       Additionally  to  interpolation	%(known/parameter)s,  that  does  not  works  for  filter/action  init	parameters,  an  interpolation tag
       <known/parameter> can be used (means last known init definition of filters or actions with name parameter). This interpolation makes possi-
       ble  to	extend a parameters of stock filter or action directly in jail inside jail.conf/jail.local file without creating a separately fil-
       ter.d/*.local file, e.g.

	      # filter.d/test.conf:
	      [Init]
	      test.method = GET
	      baduseragents = IE|wget
	      [Definition]
	      failregex = ^%(__prefix_line)s+"<test.method>"s+tests+regexps+-s+useragent=(?:<baduseragents>)

	      # jail.local:
	      [test]
	      # use filter "test", overwrite method to "POST" and extend known bad agents with "badagent":
	      filter = test[test.method=POST, baduseragents="badagent|<known/baduseragents>"]

       Comments: use '#' for comment lines and '; ' (space is important) for inline comments. When using Python2.X, '; ' can only be used  on  the
       first line due to an Python library bug.

FAIL2BAN CONFIGURATION FILE(S) (fail2ban.conf)
       These files have one section, [Definition].

       The items that can be set are:

       loglevel
	      verbosity  level of log output: CRITICAL, ERROR, WARNING, NOTICE, INFO, DEBUG, TRACEDEBUG, HEAVYDEBUG or corresponding numeric value
	      (50-5). Default: ERROR (equal 40)

       logtarget
	      log target: filename, SYSLOG, STDERR or STDOUT. Default: STDOUT if not set in fail2ban.conf/fail2ban.local
	      Note. If fail2ban running as systemd-service, for logging to the systemd-journal, the logtarget could be set to STDOUT
	      Only a single log target can be specified.  If you change logtarget from the default value and  you  are	using  logrotate  --  also
	      adjust or disable rotation in the corresponding configuration file (e.g. /etc/logrotate.d/fail2ban on Debian systems).

       socket socket filename.	Default: /var/run/fail2ban/fail2ban.sock
	      This  is	used  for  communication with the fail2ban server daemon. Do not remove this file when Fail2ban is running. It will not be
	      possible to communicate with the server afterwards.

       pidfile
	      PID filename.  Default: /var/run/fail2ban/fail2ban.pid
	      This is used to store the process ID of the fail2ban server.

       dbfile Database filename. Default: /var/lib/fail2ban/fail2ban.sqlite3
	      This defines where the persistent data for fail2ban is stored. This persistent data allows bans to be reinstated and continue  read-
	      ing log files from the last read position when fail2ban is restarted. A value of None disables this feature.

       dbpurgeage
	      Database purge age in seconds. Default: 86400 (24hours)
	      This sets the age at which bans should be purged from the database.

JAIL CONFIGURATION FILE(S) (jail.conf)
       The  following  options	are  applicable  to  any jail. They appear in a section specifying the jail name or in the [DEFAULT] section which
       defines default values to be used if not specified in the individual section.

       filter name of the filter -- filename of the filter in /etc/fail2ban/filter.d/ without the .conf/.local extension.
	      Only one filter can be specified.

       logpath
	      filename(s) of the log files to be monitored, separated by new lines.
	      Globs -- paths containing * and ? or [0-9] -- can be used however only the files that exist at start up matching this  glob  pattern
	      will be considered.

	      Optional	space  separated  option  'tail'  can  be added to the end of the path to cause the log file to be read from the end, else
	      default 'head' option reads file from the beginning

	      Ensure syslog or the program that generates the log file isn't configured to  compress  repeated	log  messages  to  "*last  message
	      repeated 5 time*s" otherwise it will fail to detect. This is called RepeatedMsgReduction in rsyslog and should be Off.

       logencoding
	      encoding of log files used for decoding. Default value of "auto" uses current system locale.

       logtimezone
	      Force the time zone for log lines that don't have one.

	      If  this	option	is not specified, log lines from which no explicit time zone has been found are interpreted by fail2ban in its own
	      system time zone, and that may turn to be inappropriate. While the best practice is  to  configure  the  monitored  applications	to
	      include explicit offsets, this option is meant to handle cases where that is not possible.

	      The supported time zones in this option are those with fixed offset: Z, UTC[+-]hhmm (you can also use GMT as an alias to UTC).

	      This option has no effect on log lines on which an explicit time zone has been found.  Examples:

		      logtimezone = UTC
		      logtimezone = UTC+0200
		      logtimezone = GMT-0100

       banaction
	      banning action (default iptables-multiport) typically specified in the [DEFAULT] section for all jails.
	      This  parameter  will  be  used  by the standard substitution of action and can be redefined central in the [DEFAULT] section inside
	      jail.local (to apply it to all jails at once) or separately in each jail, where this substitution will be used.

       banaction_allports
	      the same as banaction but for some "allports" jails like "pam-generic" or "recidive" (default iptables-allports).

       action action(s) from /etc/fail2ban/action.d/ without the .conf/.local extension.
	      Arguments can be passed to actions to override the default values from the [Init] section in the action file. Arguments  are  speci-
	      fied by:

		     [name=value,name2=value,name3="values,values"]

	      Values can also be quoted (required when value includes a ","). More that one action can be specified (in separate lines).

       ignoreself
	      boolean value (default true) indicates the banning of own IP addresses should be prevented

       ignoreip
	      list  of	IPs  not  to  ban. They can include a DNS resp. CIDR mask too. The option affects additionally to ignoreself (if true) and
	      don't need to contain own DNS resp. IPs of the running host.

       ignorecommand
	      command that is executed to determine if the current candidate IP for banning (or failure-ID for raw IDs) should not be banned.  The
	      option affects additionally to ignoreself and ignoreip and will be first executed if both don't hit.
	      IP  will	not be banned if command returns successfully (exit code 0).  Like ACTION FILES, tags like <ip> are can be included in the
	      ignorecommand value and will be substituted before execution. Currently only <ip> is supported however more will be added later.

       bantime
	      effective ban duration (in seconds or time abbreviation format).

       findtime
	      time interval (in seconds or time abbreviation format) before the current time where failures will count towards a ban.

       maxretry
	      number of failures that have to occur in the last findtime seconds to ban then IP.

       backend
	      backend to be used to detect changes in the logpath.
	      It defaults to "auto" which will try "pyinotify", "gamin", "systemd" before "polling". Any of these can be specified. "pyinotify" is
	      only valid on Linux systems with the "pyinotify" Python libraries. "gamin" requires the "gamin" libraries.

       usedns use  DNS	to resolve HOST names that appear in the logs. By default it is "warn" which will resolve hostnames to IPs however it will
	      also log a warning. If you are using DNS here you could be blocking the wrong IPs due to the asymmetric nature of reverse DNS  (that
	      the  application used to write the domain name to log) compared to forward DNS that fail2ban uses to resolve this back to an IP (but
	      not necessarily the same one). Ideally you should configure your applications to log a real IP. This can be set to "yes" to  prevent
	      warnings in the log or "no" to disable DNS resolution altogether (thus ignoring entries where hostname, not an IP is logged)..

       failregex
	      regex  (Python  regular  expression)  to	be  added to the filter's failregexes. If this is useful for others using your application
	      please share you regular expression with the fail2ban developers by reporting an issue (see REPORTING BUGS below).

       ignoreregex
	      regex which, if the log line matches, would cause Fail2Ban not consider that line.  This line will be ignored even if it	matches  a
	      failregex of the jail or any of its filters.

   Backends
       Available options are listed below.

       pyinotify
	      requires pyinotify (a file alteration monitor) to be installed. If pyinotify is not installed, Fail2ban will use auto.

       gamin  requires Gamin (a file alteration monitor) to be installed. If Gamin is not installed, Fail2ban will use auto.

       polling
	      uses a polling algorithm which does not require external libraries.

       systemd
	      uses  systemd  python  library  to access the systemd journal. Specifying logpath is not valid for this backend and instead utilises
	      journalmatch from the jails associated filter config.

   Actions
       Each jail can be configured with only a single filter, but may have multiple actions. By default, the name of a action is the action  file-
       name,  and  in the case of Python actions, the ".py" file extension is stripped. Where multiple of the same action are to be used, the act-
       name option can be assigned to the action to avoid duplication e.g.:

       [ssh-iptables-ipset]
       enabled = true
       action = smtp.py[dest=chris@example.com, actname=smtp-chris]
		smtp.py[dest=sally@example.com, actname=smtp-sally]

TIME ABBREVIATION FORMAT

       The time entries in fail2ban configuration (like findtime or bantime) can be provided as integer in seconds  or	as  string  using  special
       abbreviation format (e. g. 600 is the same as 10m).

       Abbreviation tokens:

	      years?, yea?, yy?
	      months?, mon?
	      weeks?, wee?, ww?
	      days?, da, dd?
	      hours?, hou?, hh?
	      minutes?, min?, mm?
	      seconds?, sec?, ss?

	      The question mark (?) means the optional character, so day as well as days can be used.

       You can combine multiple tokens in format (separated with space resp. without separator), e. g.: 1y 6mo or 1d12h30m.
       Note that tokens m as well as mm means minutes, for month use abbreviation mo or mon.

       The time format can be tested using fail2ban-client:

	      fail2ban-client --str2sec 1d12h

ACTION CONFIGURATION FILES (action.d/*.conf)
       Action files specify which commands are executed to ban and unban an IP address.

       Like  with jail.conf files, if you desire local changes create an [actionname].local file in the /etc/fail2ban/action.d directory and over-
       ride the required settings.

       Action files have two sections, Definition and Init .

       The [Init] section enables action-specific settings. In jail.conf/jail.local these can be overridden for a particular jail  as  options	of
       the action's specification in that 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
	      command(s) 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.

       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 are special tags which can be set in the [Init] section:

       timeout
	      The maximum period of time in seconds that a command can executed, before being killed.

       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
       "set <JAIL> action <ACT>" command. <br> is a tag that is always a new line (
).

       More than a single command is allowed to be specified. Each command needs to be on a separate line and indented with whitespace(s)  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     IPv4 IP address to be banned. e.g. 192.168.0.2

       failures
	      number of times the failure occurred in the log file. e.g. 3

       ipfailures
	      As per failures, but total of all failures for that ip address across all jails from the fail2ban persistent database. Therefore the
	      database must be set for this tag to function.

       ipjailfailures
	      As per ipfailures, but total based on the IPs failures for the current jail.

       time   UNIX (epoch) time of the ban. e.g. 1357508484

       matches
	      concatenated string of the log file lines of the matches that generated the ban. Many characters interpreted by shell get escaped to
	      prevent injection, nevertheless use with caution.

       ipmatches
	      As  per matches, but includes all lines for the IP which are contained with the fail2ban persistent database. Therefore the database
	      must be set for this tag to function.

       ipjailmatches
	      As per ipmatches, but matches are limited for the IP and for the current jail.

PYTHON ACTION FILES

       Python based actions can also be used, where the file name must be [actionname].py. The Python file must contain a  variable  Action  which
       points  to  Python  class.  This  class	must implement a minimum interface as described by fail2ban.server.action.ActionBase, which can be
       inherited from to ease implementation.

FILTER FILES (filter.d/*.conf)
       Filter definitions are those in /etc/fail2ban/filter.d/*.conf and filter.d/*.local.

       These are used to identify failed authentication attempts in log files 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 if usedns). Fail2Ban will work out which one of these it actually is.  For multiline regexs the
	      tag <SKIPLINES> should be used to separate lines. This allows lines between the matched lines to continue to be searched	for  other
	      failures. The tag can be used multiple times.

       ignoreregex
	      is the regex to identify log entries that should be ignored by Fail2Ban, even if they match failregex.

       Similar	to  actions, filters have an [Init] section which can be overridden in jail.conf/jail.local. Besides the filter-specific settings,
       the filter [Init] section can be used to set following standard options:

       maxlines
	      specifies the maximum number of lines to buffer to match multi-line regexs. For some log	formats  this  will  not  required  to	be
	      changed. Other logs may require to increase this value if a particular log file is frequently written to.

       datepattern
	      specifies  a  custom  date  pattern/regex as an alternative to the default date detectors e.g. %Y-%m-%d %H:%M(?::%S)?. For a list of
	      valid format directives, see Python library documentation for strptime behaviour.
	      Also, special values of Epoch (UNIX Timestamp), TAI64N and ISO8601 can be used.
	      NOTE: due to config file string substitution, that %'s must be escaped by an % in config files.

       journalmatch
	      specifies the systemd journal match used to filter the journal entries. See journalctl(1) and systemd.journal-fields(7) for  matches
	      syntax and more details on special journal fields. This option is only valid for the systemd backend.

       Similar to actions [Init] section enables filter-specific settings. All parameters specified in [Init] section can be redefined or extended
       in jail.conf/jail.local.

       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.

AUTHOR

       Fail2ban was originally written by Cyril Jaquier <cyril.jaquier@fail2ban.org>.  At the moment it is maintained  and  further  developed	by
       Yaroslav  O.  Halchenko	<debian@onerussian.com>,  Daniel  Black  <daniel.subs@internode.on.net>  and Steven Hiscocks <steven-fail2ban@his-
       cocks.me.uk> along with a number of contributors.  See THANKS file shipped with Fail2Ban for a full list.  Manual page  written	by  Daniel
       Black and Yaroslav Halchenko.

REPORTING BUGS

       Report bugs to https://github.com/fail2ban/fail2ban/issues

COPYRIGHT

       Copyright (C) 2013 the Fail2Ban Team
       Copyright of modifications held by their respective authors.
       Licensed under the GNU General Public License v2 (GPL) or (at your option) any later version.

SEE ALSO

       fail2ban-server(1)

Fail2Ban							   November 2015						      JAIL.CONF(5)