Provided by: fail2ban_0.10.2-2_all bug


       jail.conf - configuration for the fail2ban server


       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


       Fail2ban has four configuration file types:

              Fail2Ban global configuration (such as logging)

              Filters specifying how to detect authentication failures

              Actions defining the commands for banning and unbanning of IP address

              Jails defining combinations of Filters with Actions.


       *.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


              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.d/*.conf (in alphabetical order)
              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),

              baduseragents = IE|wget|%(my-settings/baduseragents)s
              failregex = %(known/failregex)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:
              test.method = GET
              baduseragents = IE|wget
              failregex = ^%(__prefix_line)\s+"<test.method>"\s+test\s+regexp\s+-\s+useragent=(?:<baduseragents>)

              # jail.local:
              # 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


       These files have one section, [Definition].

       The items that can be set are:

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

              log  target:  filename,  SYSLOG,  STDERR  or  STDOUT. Default: STDOUT if not set in
              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

       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.

              PID filename.  Default: /var/run/fail2ban/
              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.

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


       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.

              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

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

              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

              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.

              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:


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

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

              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.

              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.

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

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

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

              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"

       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)..

              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).

              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

       Available options are listed below.

              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.

              uses a polling algorithm which does not require external libraries.

              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.

       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.:

       enabled = true
       action =[, actname=smtp-chris]
      [, actname=smtp-sally]


       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 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.

              command(s) executed when the jail starts.

              command(s) executed when the jail stops.

              command(s)  ran  before  any  other action. It aims to verify if the environment is
              still ok.

              command(s) that bans the IP address after maxretry log lines  matches  within  last
              findtime seconds.

              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:

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

       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.

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

              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.

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

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

              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.

              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

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


       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]

       There are two filter definitions used in the [Definition] section:

              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.

              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:

              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.

              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.

              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.


       Fail2ban was originally written by Cyril  Jaquier  <>.   At  the
       moment   it   is   maintained   and   further   developed   by   Yaroslav   O.   Halchenko
       <>, Daniel Black <> and  Steven  Hiscocks
       <>  along  with  a  number of contributors.  See THANKS file
       shipped with Fail2Ban for a full list.  Manual page written by Daniel Black  and  Yaroslav


       Report bugs to


       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