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NAME

       firehol-defaults.conf - control variables for FireHOL

SYNOPSIS

       Defaults in /etc/firehol/firehol-defaults.conf:

       · DEFAULT_INTERFACE_POLICY="DROP"

       · DEFAULT_ROUTER_POLICY="RETURN"

       · UNMATCHED_INPUT_POLICY="DROP"

       · UNMATCHED_OUTPUT_POLICY="DROP"

       · UNMATCHED_FORWARD_POLICY="DROP"

       · FIREHOL_INPUT_ACTIVATION_POLICY="ACCEPT"

       · FIREHOL_OUTPUT_ACTIVATION_POLICY="ACCEPT"

       · FIREHOL_FORWARD_ACTIVATION_POLICY="ACCEPT"

       · FIREHOL_LOG_MODE="LOG"

       · FIREHOL_LOG_LEVEL=see notes

       · FIREHOL_LOG_OPTIONS="--log-level warning"

       · FIREHOL_LOG_FREQUENCY="1/second"

       · FIREHOL_LOG_BURST="5"

       · FIREHOL_LOG_PREFIX=""

       · FIREHOL_DROP_INVALID="0"

       · DEFAULT_CLIENT_PORTS="1000:65535"

       · FIREHOL_NAT="0"

       · FIREHOL_ROUTING="0"

       · FIREHOL_AUTOSAVE=see notes

       · FIREHOL_AUTOSAVE6=see notes

       · FIREHOL_LOAD_KERNEL_MODULES="1"

       · FIREHOL_TRUST_LOOPBACK="1"

       · FIREHOL_DROP_ORPHAN_TCP_ACK_FIN="1"

       · FIREHOL_DROP_ORPHAN_TCP_ACK_RST="1"

       · FIREHOL_DROP_ORPHAN_TCP_ACK="1"

       · FIREHOL_DROP_ORPHAN_TCP_RST="1"

       · FIREHOL_DROP_ORPHAN_IPV4_ICMP_TYPE3="1"

       · WAIT_FOR_IFACE=""

DESCRIPTION

       From  FireHOL  3 upwards, variables which control FireHOL behaviour are held in a separate
       file: /etc/firehol/firehol-defaults.conf.

       Some variables can also be set in the main firehol.conf file but that is not  recommended,
       since they may be used before the main configuration is processed.

       FireHOL  also  sets  some variables before processing the configuration file which you can
       use as part of your configuration.  These are described in firehol.conf(5).

VARIABLES

       DEFAULT_INTERFACE_POLICY
              This variable controls the default action to be taken on traffic not matched by any
              rule within an interface.  It can be overridden using firehol-policy(5).

              Packets  that  reach  the end of an interface without an action of return or accept
              are  logged.   You  can  control  the  frequency  of  this  logging   by   altering
              FIREHOL_LOG_FREQUENCY.

              Example:

                     DEFAULT_INTERFACE_POLICY="REJECT"

       DEFAULT_ROUTER_POLICY
              This variable controls the default action to be taken on traffic not matched by any
              rule within a router.  It can be overridden using firehol-policy(5).

              Packets that reach the end of a router without an action of return  or  accept  are
              logged.    You   can   control   the   frequency   of   this  logging  by  altering
              FIREHOL_LOG_FREQUENCY.

              Example:

                     DEFAULT_ROUTER_POLICY="REJECT"

       UNMATCHED_{INPUT|OUTPUT|FORWARD}_POLICY
              These variables control the default action to be taken on traffic  not  matched  by
              any  interface  or  router definition that was incoming, outgoing or for forwarding
              respectively.  Any supported value from firehol-actions(5) may be set.

              All packets that reach the end of a chain are logged, regardless of these settings.
              You can control the frequency of this logging by altering FIREHOL_LOG_FREQUENCY.

              Example:

                     UNMATCHED_INPUT_POLICY="REJECT"
                     UNMATCHED_OUTPUT_POLICY="REJECT"
                     UNMATCHED_FORWARD_POLICY="REJECT"

       FIREHOL_{INPUT|OUTPUT|FORWARD}_ACTIVATION_POLICY
              These  variables  control the default action to be taken on traffic during firewall
              activation for incoming, outgoing and forwarding respectively.   Acceptable  values
              are ACCEPT, DROP and REJECT.

              FireHOL  defaults all values to ACCEPT so that your communications continue to work
              uninterrupted.

              If you wish to prevent connections whilst the new firewall is activating, set these
              values  to  DROP.   This  is  important  to do if you are using all or any to match
              traffic; connections established during activation will continue even if they would
              not be allowed once the firewall is established.

              Example:

                     FIREHOL_INPUT_ACTIVATION_POLICY="DROP"
                     FIREHOL_OUTPUT_ACTIVATION_POLICY="DROP"
                     FIREHOL_FORWARD_ACTIVATION_POLICY="DROP"

       FIREHOL_LOG_MODE
              This variable controls method that FireHOL uses for logging.

              Acceptable values are LOG (normal syslog) and ULOG (netfilter ulogd).  When ULOG is
              selected, FIREHOL_LOG_LEVEL is ignored.

              Example:

                     FIREHOL_LOG_MODE="ULOG"

              To   see   the   available    options    run:    /sbin/iptables -j LOG --help    or
              /sbin/iptables -j ULOG --help

       FIREHOL_LOG_LEVEL
              This variable controls the level at which events will be logged to syslog.

              To  avoid  packet  logs appearing on your console you should ensure klogd only logs
              traffic that is more important than that produced by FireHOL.

              Use the following option to choose an iptables(8)  log  level  (alpha  or  numeric)
              which is higher than the -c of klogd.

              iptables/klogd levels

              iptables      klogd   description
              ───────────────────────────────────────────────
              emerg (0)     0       system is unusable
              alert (1)     1       action   must  be  taken
                                    immediately
              crit (2)      2       critical conditions
              error (3)     3       error conditions
              warning (4)   4       warning conditions
              notice (5)    5       normal  but  significant
                                    condition
              info (6)      6       informational
              debug (7)     7       debug-level messages

                     Note

                     The  default  for klogd is generally to log everything (7 and lower) and the
                     default level for iptables(4) is to log as warning (4).

       FIREHOL_LOG_OPTIONS
              This variable controls the way in which events will be logged to syslog.

              Example:

                     FIREHOL_LOG_OPTIONS="--log-level info \
                                          --log-tcp-options --log-ip-options"

              To see the available options run: /sbin/iptables -j LOG --help

       FIREHOL_LOG_FREQUENCY; FIREHOL_LOG_BURST
              These variables control the frequency that each logging rule will write  events  to
              syslog.   FIREHOL_LOG_FREQUENCY  is  set  to  the  maximum  average  frequency  and
              FIREHOL_LOG_BURST specifies the maximum initial number.

              Example:

                     FIREHOL_LOG_FREQUENCY="30/minute"
                     FIREHOL_LOG_BURST="2"

              To see the available options run: /sbin/iptables -m limit --help

       FIREHOL_LOG_PREFIX
              This value is added to the contents of each  logged  line  for  easy  detection  of
              FireHOL lines in the system logs.  By default it is empty.

              Example:

                     FIREHOL_LOG_PREFIX="FIREHOL:"

       FIREHOL_DROP_INVALID
              If set to 1, this variable causes FireHOL to drop all packets matched as INVALID in
              the iptables(8) connection tracker.

              You may be better off using firehol-protection(5) to control  matching  of  INVALID
              packets and others on a per-interface and per-router basis.

                     Note

                     Care  must  be  taken  on  IPv6  interfaces,  since  ICMPv6  packets such as
                     Neighbour Discovery are not tracked, meaning they are marked as INVALID.

              Example:

                     FIREHOL_DROP_INVALID="1"

       DEFAULT_CLIENT_PORTS
              This variable controls the port  range  that  is  used  when  a  remote  client  is
              specified.   For clients on the local host, FireHOL finds the exact client ports by
              querying the kernel options.

              Example:

                     DEFAULT_CLIENT_PORTS="0:65535"

       FIREHOL_NAT
              If set to 1, this variable causes FireHOL to load the NAT kernel modules.   If  you
              make use of the NAT helper commands, the variable will be set to 1 automatically.

              Example:

                     FIREHOL_NAT="1"

       FIREHOL_ROUTING
              If  set to 1, this variable causes FireHOL to enable routing in the kernel.  If you
              make use of router definitions or certain helper commands the variable will be  set
              to 1 automatically.

              Example:

                     FIREHOL_ROUTING="1"

       FIREHOL_AUTOSAVE; FIREHOL_AUTOSAVE6
              These  variables  specify  the  file  of  IPv4/IPv6 rules that will be created when
              firehol(1) is called with the save argument.

              If the variable is not set, a system-specific value is used which  was  defined  at
              configure-time.  If no value was chosen then the save fails.

              Example:

                     FIREHOL_AUTOSAVE="/tmp/firehol-saved-ipv4.txt"
                     FIREHOL_AUTOSAVE6="/tmp/firehol-saved-ipv6.txt"

       FIREHOL_LOAD_KERNEL_MODULES
              If  set  to  0, this variable forces FireHOL to not load any kernel modules.  It is
              needed only if the kernel has modules statically included and  in  the  rare  event
              that FireHOL cannot access the kernel configuration.

              Example:

                     FIREHOL_LOAD_KERNEL_MODULES="0"

       FIREHOL_TRUST_LOOPBACK
              If  set  to  0,  the  loopback  device  "lo"  will not be trusted and you can write
              standard firewall rules for it.

                     Warning

                     If you do not set up appropriate rules, local processes will not be able  to
                     communicate with each other which can result in serious breakages.

              By default "lo" is trusted and all INPUT and OUTPUT traffic is accepted (forwarding
              is not included).

              Example:

                     FIREHOL_TRUST_LOOPBACK="0"

       FIREHOL_DROP_ORPHAN_TCP_ACK_FIN
              If set to 1, FireHOL will drop all orphan such packets without logging them.

              In busy environments the iptables(8) connection tracker removes connection tracking
              list  entries  as  soon  as it receives a FIN.  This makes the ACK FIN appear as an
              invalid packet which will normally be logged by FireHOL.

              Example:

                     FIREHOL_DROP_ORPHAN_TCP_ACK_FIN="1"

       FIREHOL_DROP_ORPHAN_TCP_ACK_RST
              If set to 1, FireHOL will drop all orphan such packets without logging them.

              In busy environments the iptables(8) connection tracker removes connection tracking
              list  entries  as  soon  as it receives a RST.  This makes the ACK RST appear as an
              invalid packet which will normally be logged by FireHOL.

              Example:

                     FIREHOL_DROP_ORPHAN_TCP_ACK_RST="1"

       FIREHOL_DROP_ORPHAN_TCP_ACK
              If set to 1, FireHOL will drop all orphan such packets without logging them.

              In busy environments the iptables(8) connection tracker removes unneeded connection
              tracking  list  entries.   This makes ACK packets appear as an invalid packet which
              will normally be logged by FireHOL.

              Example:

                     FIREHOL_DROP_ORPHAN_TCP_ACK="1"

       FIREHOL_DROP_ORPHAN_TCP_RST
              If set to 1, FireHOL will drop all orphan such packets without logging them.

              In busy environments the iptables(8) connection tracker removes unneeded connection
              tracking  list  entries.   This makes RST packets appear as an invalid packet which
              will normally be logged by FireHOL.

              Example:

                     FIREHOL_DROP_ORPHAN_TCP_RST="1"

       FIREHOL_DROP_ORPHAN_IPV4_ICMP_TYPE3
              If set to 1, FireHOL will drop all  orphan  ICMP  destination  unreachable  packets
              without logging them.

              In busy environments the iptables(8) connection tracker removes unneeded connection
              tracking list entries.  This  makes  ICMP  destination  unreachable  appear  as  an
              invalid packet which will normally be logged by FireHOL.

              Example:

                     FIREHOL_DROP_ORPHAN_IPV4_ICMP_TYPE3="1"

       WAIT_FOR_IFACE
              If  set  to  the name of a network device (e.g.  eth0), FireHOL will wait until the
              device is up (or until 60 seconds have elapsed) before continuing.

              A device does not need to be up in order to have firewall rules created for it,  so
              this  option  should  only  be  used if you have a specific need to wait (e.g.  the
              network must be queried to determine the hosts or ports which will be firewalled).

              Example:

                     WAIT_FOR_IFACE="eth0"

SEE ALSO

       · firehol(1) - FireHOL program

       · firehol.conf(5) - FireHOL configuration

       · firehol-nat(5) - nat, snat, dnat, redirect helpers

       · firehol-actions(5) - actions for rules

       · iptables(8) (http://ipset.netfilter.org/iptables.man.html)  -  administration  tool  for
         IPv4 firewalls

       · ip6tables(8)  (http://ipset.netfilter.org/ip6tables.man.html)  - administration tool for
         IPv6 firewalls

       · FireHOL Website (http://firehol.org/)

       · FireHOL Online PDF Manual (http://firehol.org/firehol-manual.pdf)

       · FireHOL Online Documentation (http://firehol.org/documentation/)

AUTHORS

       FireHOL Team.