Provided by: fail2ban_0.10.2-2_all bug

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, customizations 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 multiple 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 possible to extend a parameters of stock filter or
       action directly in jail inside jail.conf/jail.local file without creating a  separately  filter.d/*.local
       file, e.g.

              # filter.d/test.conf:
              [Init]
              test.method = GET
              baduseragents = IE|wget
              [Definition]
              failregex = ^%(__prefix_line)\s+"<test.method>"\s+test\s+regexp\s+-\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  reading  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 specified 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 filename, and in the case of Python actions, the ".py" file  extension  is
       stripped.  Where  multiple  of  the same action are to be used, the actname 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 override 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 (\n).

       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@hiscocks.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 © 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)