Provided by: shorewall-common_4.0.6-1_all bug


       shorewall.conf - Shorewall global configuration file




       This file sets options that apply to Shorewall as a whole.

       The  file  consists of Shell comments (lines beginning with ’#’), blank
       lines and assignment statements (variable=value).


       Many options have as their value a log-level.  Log levels are a  method
       of describing to syslog (8) the importance of a message and a number of
       parameters in this file have log levels as their value.

       These levels are defined by  syslog  and  are  used  to  determine  the
       destination  of  the  messages through entries in /etc/syslog.conf (5).
       The syslog documentation refers to  these  as  "priorities";  Netfilter
       calls them "levels" and Shorewall also uses that term.

       Valid levels are:

              7       debug
              6       info
              5       notice
              4       warning
              3       err
              2       crit
              1       alert
              0       emerg

       For  most  Shorewall  logging,  a  level  of  6  (info) is appropriate.
       Shorewall log messages are generated by NetFilter and are logged  using
       facility  ’kern’ and the level that you specifify. If you are unsure of
       the level to choose, 6 (info) is a safe bet. You may specify levels  by
       name or by number.

       If  you  have  built your kernel with ULOG target support, you may also
       specify a log level of ULOG (must be all caps).  Rather  than  log  its
       messages  to  syslogd,  Shorewall  will  direct  netfilter  to  log the
       messages via the ULOG target which will send them to a  process  called
       ’ulogd’.  ulogd is available with most Linux distributions (although it
       probably isn’t installed by default).  Ulogd  is  also  available  from
       〈〉    and    can   be
       configured to log all Shorewall message to their own log file

       The following options may be set in shorewall.conf.





       NFQUEUE_DEFAULT={action|macro|none} (Shorewall-perl 4.0.3 and later)
              In earlier Shorewall versions, a "default action" for  DROP  and
              REJECT     policies     was     specified     in     the    file

              To allow for default rules to be  applied  when  USE_ACTIONS=No,
              and NFQUEUE_DEFAULT options have been added.

              DROP_DEFAULT  describes  the  rules  to  be  applied  before   a
              connection  request  is dropped by a DROP policy; REJECT_DEFAULT
              describes the rules to be applied if  a  connection  request  is
              rejected  by  a  REJECT  policy. The other three are similar for
              ACCEPT, QUEUE and NFQUEUE policies.

              The value applied to these may be:

              a) The name of an action.
              b) The name of a macro (Shorewall-shell only)
              c) None or none

              The default values are:


              If USE_ACTIONS=Yes, then these values refer to  action.Drop  and
              action.Reject respectively. If USE_ACTIONS=No, then these values
              refer to macro.Drop and macro.Reject.

              If you set the value of either option to "None" then no  default
              action  will  be  used  and  the default action or macro must be
              specified in shorewall-policy 〈shorewall-policy.html〉 (5).

              This parameter determines whether Shorewall  automatically  adds
              the  external  address(es) in shorewall-nat 〈shorewall-nat.html〉
              (5). If the variable  is  set  to  Yes  or  yes  then  Shorewall
              automatically  adds these aliases. If it is set to No or no, you
              must  add  these  aliases  yourself  using  your  distribution’s
              network configuration tools.

              If  this  variable  is  not  set  or  is  given  an  empty value
              (ADD_IP_ALIASES="") then ADD_IP_ALIASES=Yes is assumed.

              Addresses added by ADD_IP_ALIASES=Yes are deleted  and  re-added
              during  shorewall  restart.  As a consequence, connections using
              those addresses may be severed.

              This parameter determines whether Shorewall  automatically  adds
              the SNAT ADDRESS in shorewall-masq 〈shorewall-masq.html〉 (5). If
              the variable is set to Yes or yes then  Shorewall  automatically
              adds  these  addresses.  If  it is set to No or no, you must add
              these  addresses  yourself  using  your  distribution’s  network
              configuration tools.

              If  this  variable  is  not  set  or  is  given  an  empty value
              (ADD_SNAT_ALIASES="") then ADD_SNAT_ALIASES=No is assumed.

              Addresses added by ADD_SNAT_ALIASES=Yes are deleted and re-added
              during  shorewall  restart.  As a consequence, connections using
              those addresses may be severed.

              The value of this variable affects  Shorewall’s  stopped  state.
              When   ADMINISABSENTMINDED=No,   only   traffic   to/from  those
              addresses        listed        in         shorewall-routestopped
              〈shorewall-routestopped.html〉  (5) is accepted when Shorewall is
              stopped. When ADMINISABSENTMINDED=Yes, in  addition  to  traffic
              to/from        addresses        in        shorewall-routestopped
              〈shorewall-routestopped.html〉 (5), connections that were  active
              when  Shorewall stopped continue to work and all new connections
              from the firewall system itself are allowed.  If  this  variable
              is    not    set    or   is   given   the   empty   value   then
              ADMINISABSENTMINDED=No is assumed.

              Setting this option to ’Yes’ allows you to  include  arbitrarily
              long destination port lists in all configuration files.

              This  parameter  determines  the  disposition  of  packets  from
              blacklisted hosts. It may have the value DROP if the packets are
              to be dropped or REJECT if the packets are to be replied with an
              ICMP port unreachable reply or a TCP RST (tcp only). If  you  do
              not  assign a value or if you assign an empty value then DROP is

              This parameter determines if packets from blacklisted hosts  are
              logged  and  it  determines the syslog level that they are to be
              logged   at.   Its   value   is   a   syslog   level   (Example:
              BLACKLIST_LOGLEVEL=debug).  If  you  do not assign a value or if
              you assign an empty value then packets  from  blacklisted  hosts
              are not logged.

              When  set  to  Yes or yes, blacklists are only consulted for new
              connections. When set to No or no, blacklists are consulted  for
              every packet (will slow down your firewall noticably if you have
              large blacklists). If the BLACKLISTNEWONLY option is not set  or
              is set to the empty value then BLACKLISTNEWONLY=No is assumed.

              BLACKLISTNEWONLY=No is incompatible with FASTACCEPT=Yes.

              When set to Yes or yes, enables Shorewall Bridging support.


              BRIDGING=Yes  may  not work properly with Linux kernel 2.6.20 or
              later and is not supported by Shorewall-perl.

              This parameter enables the TCP Clamp  MSS  to  PMTU  feature  of
              Netfilter  and is usually required when your internet connection
              is through PPPoE or PPTP. If set to Yes or yes, the  feature  is
              enabled.  If  left  blank or set to No or no, the feature is not

              Important: This option  requires  CONFIG_IP_NF_TARGET_TCPMSS  in
              your kernel.

              You   may   also   set   CLAMPMSS  to  a  numeric  value  (e.g.,
              CLAMPMSS=1400). This will set the MSS field in TCP  SYN  packets
              going through the firewall to the value that you specify.

              If  this  option  is  set  to  No then Shorewall won’t clear the
              current traffic control rules during [re]start. This setting  is
              intended  for  use  by  people  that prefer to configure traffic
              shaping when the network interfaces come up rather than when the
              firewall  is  started.  If  that  is  what  you  want to do, set
              TC_ENABLED=Yes  and   CLEAR_TC=No   and   do   not   supply   an
              /etc/shorewall/tcstart  file.  That  way,  your  traffic shaping
              rules can still use the  “fwmark”  classifier  based  on  packet
              marking  defined  in  shorewall-tcrules 〈shorewall-tcrules.html〉
              (5). If not specified, CLEAR_TC=Yes is assumed.

              Specifies where configuration files  other  than  shorewall.conf
              may  be  found.  CONFIG_PATH is specifies as a list of directory
              names  separated  by  colons   (":").   When   looking   for   a
              configuration file other than shorewall.conf:

              · If  the  command is "try" or if "-c <configuration directory>"
                was specified in the command then the directory given  in  the
                command is searched first.

              · Next, each directory in the CONFIG_PATH setting is searched in

              If CONFIG_PATH is not given or if it is set to the  empty  value
              then  the  contents of /usr/share/shorewall/configpath are used.
              As released from, that file sets  the  CONFIG_PATH
              to   /etc/shorewall:/usr/share/shorewall   but  your  particular
              distribution may set it differently. See the output of shorewall
              show config for the default on your system.

              Note  that  the  setting  in  /usr/share/shorewall/configpath is
              always used to locate shorewall.conf.

              Users with a  large  static  black  list  (  shorewall-blacklist
              〈shorewall-blacklist.html〉    (5))   may   want   to   set   the
              DELAYBLACKLISTLOAD option to Yes.  When  DELAYBLACKLISTLOAD=Yes,
              Shorewall   will  enable  new  connections  before  loading  the
              blacklist  rules.   While  this  may  allow   connections   from
              blacklisted   hosts  to  slip  by  during  construction  of  the
              blacklist, it can substantially reduce the  time  that  all  new
              connections are disabled during shorewall [re]start.

              DELAYBLACKLISTLOAD=Yes is not supported by Shorewall-perl.

              Added  in  Shorewall  4.0.4.  If set to Yes (the default value),
              entries in the /etc/shorewall/route_stopped files cause  an  ’ip
              rule  del’  command  to  be generated in addition to an ’ip rule
              add’ command. Setting this option to No,  causes  the  ’ip  rule
              del’ command to be omitted.

              If set to Yes or yes, Shorewall will detect the first IP address
              of the interface to  the  source  zone  and  will  include  this
              address in DNAT rules as the original destination IP address. If
              set to No or no, Shorewall will not detect this address and  any
              destination  IP  address  will  match  the  DNAT  rule.  If  not
              specified or empty, “DETECT_DNAT_IPADDRS=Yes” is assumed.

              Added in Shorewall-4.0.6.  Causes  Shorewall  to  not  load  the
              listed modules.

              When set to Yes or yes, enables dynamic zones. DYNAMIC_ZONES=Yes
              is not allowed in configurations that will run  under  Shorewall

              Normally, when the SOURCE or DEST columns in shorewall-policy(5)
              contains ’all’, a single policy chain is created and the  policy
              is enforced in that chain. For example, if the policy entry is

              #                   LEVEL
              net     all  DROP   info

              then  the  chain name is ’net2all’ which is also the chain named
              in Shorewall log messages generated as a result of  the  policy.
              If   EXPAND_POLICIES=Yes,  then  Shorewall-perl  will  create  a
              separate chain for each pair of zones  covered  by  the  policy.
              This  makes the resulting log messages easier to interpret since
              the chain in the messages will have a name  of  the  form  ’a2b’
              where ’a’ is the SOURCE zone and ’b’ is the DEST zone.

              It is quite difficult to code a ’params’ file that assigns other
              than constant values such that it works correctly with Shorewall
              Lite.  The  EXPORTPARAMS option works around this problem.  When
              EXPORTPARAMS=No, the ’params’ file is not copied to the compiler

              With EXPORTPARAMS=No, if you need to set environmental variables
              on the firewall system for use by your extension  scripts,  then
              do so in the init extension script.

              The default is EXPORTPARAMS=Yes

              Normally, Shorewall defers accepting ESTABLISHED/RELATED packets
              until these packets  reach  the  chain  in  which  the  original
              connection  was  accepted.  So  for packets going from the ’loc’
              zone to the ’net’ zone, ESTABLISHED/RELATED packets are ACCEPTED
              in the ’loc2net’ chain.

              If you set FASTACCEPT=Yes, then ESTABLISHED/RELEATED packets are
              accepted early in the INPUT, FORWARD and OUTPUT chains.  If  you
              set  FASTACCEPT=Yes  then  you  may  not  include  rules  in the
              ESTABLISHED   or    RELATED    sections    of    shorewall-rules
              〈shorewall-rules.html〉 (5).


              FASTACCEPT=Yes is incompatible with BLACKLISTNEWONLY=No.

              Prior  to  version  3.2.0, it was not possible to use connection
              marking in shorewall-tcrules 〈shorewall-tcrules.html〉 (5) if you
              have a multi-ISP configuration that uses the track option.

              Beginning    with    release    3.2.0,    you    may   now   set
              HIGH_ROUTE_MARKS=Yes in to effectively divide  the  packet  mark
              and connection mark into two 8-byte mark fields.

              When you do this:

              1.  The  MARK field in the providers file must have a value that
                  is less than 65536 and that is a multiple of 256 (using  hex
                  representation,  the  values are 0x0100-0xFF00 with the low-
                  order 8 bits being zero).

              2.  You may only set those mark values in the PREROUTING  chain.

              3.  Marks used for traffic shaping must still be in the range of
                  1-255 and may still not be set in the PREROUTING chain.

              4.  When you SAVE or RESTORE in tcrules, only the TC mark  value
                  is saved or restored. Shorewall handles saving and restoring
                  the routing (provider) marks.

              When this option is set to Yes, it causes subzones to be treated
              differently with respect to policies.

              Subzones are defined by following their name with ":" and a list
              of parent zones (in shorewall-zones 〈shorewall-zones.html〉 (5)).
              Normally,  you  want  to  have  a  set  of special rules for the
              subzone and if a connection doesn’t match any of those  subzone-
              specific  rules then you want the parent zone rules and policies
              to be applied;  see  shorewall-nesting  〈shorewall-nesting.html〉
              (5).  With IMPLICIT_CONTINUE=Yes, that happens automatically.

              If IMPLICIT_CONTINUE=No or if IMPLICIT_CONTINUE is not set, then
              subzones  are  not  subject  to  this  special  treatment.  With
              IMPLICIT_CONTINUE=Yes,   an  implicit  CONTINUE  policy  may  be
              overridden by including an explicit policy (one  that  does  not
              specify "all" in either the SOURCE or the DEST columns).

              This  parameter determines whether Shorewall enables or disables
              IPV4    Packet    Forwarding    (/proc/sys/net/ipv4/ip_forward).
              Possible values are:

              On or on
                     packet forwarding will be enabled.

              Off or off
                     packet forwarding will be disabled.

              Keep or keep
                     Shorewall   will   neither   enable  nor  disable  packet

              If this  variable  is  not  set  or  is  given  an  empty  value
              (IP_FORWARD="") then IP_FORWARD=On is assumed.

              This should be set to zones for all new Shorewall installations.
              IPSECFILE=ipsec  is  only  used  for  compatibility  with   pre-
              Shorewall-3.0 configurations.

              This  parameter  names  the  iptables  executable  to be used by
              Shorewall. If not specified or if specified  as  a  null  value,
              then  the  iptables  executable located using the PATH option is

              Regardless of how the IPTABLES utility is located (specified via
              IPTABLES=  or  located  via  PATH), Shorewall uses the iptables-
              restore and iptables-save utilities from that same directory.

              Added in Shorewall 4.0.3. When set to Yes, this option  prevents
              scripts   generated   by   Shorewall-perl   from   altering  the
              /etc/iproute2/rt_tables  database  when  there  are  entries  in
              /etc/shorewall/providers.  If  you  set this option to Yes while
              Shorewall (Shorewall-lite) is running,  you  should  remove  the
              file                                /var/lib/shorewall/rt_tables
              (/var/lib/shorewall-lite/rt_tables)  before  your   next   stop,
              refresh, restore on restart command.

              The default is KEEP_RT_TABLES=No.

              If        set        to       Yes       or       yes,       sets
              /proc/sys/net/ipv4/conf/all/log_martians                     and
              /proc/sys/net/ipv4/conf/default/log_martians to 1. Default is No
              which sets both of the above to  zero.  If  you  do  not  enable
              martian  logging for all interfaces, you may still enable it for
              individual interfaces using the logmartians interface option  in
              shorewall-interfaces 〈shorewall-interfaces.html〉 (5).

              The  value  Keep is only allowed under Shorewall-perl. It causes
              Shorewall to ignore the option. If the option  is  set  to  Yes,
              then martians are logged on all interfaces. If the option is set
              to No, then martian logging is disabled on all interfaces except
              those          specified         in         shorewall-interfaces
              〈shorewall-interfaces.html〉 (5).

              This option is intended for use as a debugging aid. When set  to
              a  log level, this option causes Shorewall to generate a logging
              rule as the first rule in each builtin chain.

              · The table name is used as the chain name in the log prefix.

              · The chain name is used as the target in the log prefix.

              For example, using the default LOGFORMAT,  the  log  prefix  for
              logging from the nat table’s PREROUTING chain is:



                     To  help  insure  that  all  packets in the NEW state are
                     logged, rate limiting (LOGBURST and LOGLIMIT)  should  be
                     disabled  when using LOGALLNEW. Use LOGALLNEW at your own
                     risk; it may cause high CPU and disk utilization and  you
                     may not be able to control your firewall after you enable
                     this option.


                     Do not use this option if the resulting log messages will
                     be sent to another system.

              This  parameter  tells the /sbin/shorewall program where to look
              for Shorewall messages when processing the dump, logwatch,  show
              log, and hits commands.  If not assigned or if assigned an empty
              value, /var/log/messages is assumed.

              The value of this variable generate the --log-prefix setting for
              Shorewall  logging  rules.  It  contains  a  “printf” formatting
              template which accepts three arguments (the chain name,  logging
              rule  number  (optional)  and the disposition). To use LOGFORMAT
              with fireparse, set it as:

                  LOGFORMAT="fp=%s:%d a=%s "

              If the LOGFORMAT value contains  the  substring  “%d”  then  the
              logging   rule  number  is  calculated  and  formatted  in  that
              position; if that substring is not included then the rule number
              is   not  included.   If  not  supplied  or  supplied  as  empty
              (LOGFORMAT="") then “Shorewall:%s:%s:” is assumed.


              These parameters set the match rate and initial burst  size  for
              logged  packets. Please see iptables(8) for a description of the
              behavior of these parameters (the iptables option --limit is set
              by  LOGRATE  and  --limit-burst  is  set  by  LOGBURST). If both
              parameters are set empty, no rate-limiting will occur.



              For each logging rule, the first time the rule is  reached,  the
              packet  will be logged; in fact, since the burst is 5, the first
              five packets will be logged. After this, it will be 6 seconds (1
              minute  divided  by  the  rate  of  10) before a message will be
              logged from the rule, regardless of how many packets  reach  it.
              Also,  every  6  seconds which passes without matching a packet,
              one of the bursts will be regained; if no packets hit  the  rule
              for 30 seconds, the burst will be fully recharged; back where we

              Using the default LOGFORMAT,  chain  names  may  not  exceed  11
              characters  or  truncation  of  the log prefix may occur. Longer
              chain names may be used with log tags if you set LOGTAGONLY=Yes.
              With  LOGTAGONLY=Yes,  if a log tag is specified then the tag is
              included in the log prefix in place of the chain name.

              Determines the disposition of connections requests that fail MAC
              Verification   and  must  have  the  value  ACCEPT  (accept  the
              connection  request  anyway),  REJECT  (reject  the   connection
              request)  or DROP (ignore the connection request). If not set or
              if set to the empty value  (e.g.,  MACLIST_DISPOSITION="")  then
              MACLIST_DISPOSITION=REJECT is assumed.

              Determines the syslog level for logging connection requests that
              fail MAC Verification. The value must be  a  valid  syslogd  log
              level.  If  you don’t want to log these connection requests, set
              to the empty value (e.g., MACLIST_LOG_LEVEL="").

              Normally, MAC verification occurs in the filter table (INPUT and
              FORWARD) chains. When forwarding a packet from an interface with
              MAC verification to a bridge interface, that doesn’t work.

              This   problem    can    be    worked    around    by    setting
              MACLIST_TABLE=mangle  which will cause Mac verification to occur
              out of the PREROUTING chain. Because REJECT isn’t  available  in
              that environment, you may not specify MACLIST_DISPOSITION=REJECT
              with MACLIST_TABLE=mangle.

              The performance  of  configurations  with  a  large  numbers  of
              entries in shorewall-maclist 〈shorewall-maclist.html〉 (5) can be
              improved by setting the MACLIST_TTL variable  in  shorewall.conf
              〈shorewall.conf.html〉 (5).

              If  your iptables and kernel support the "Recent Match" (see the
              output of "shorewall check" near the top),  you  can  cache  the
              results  of a ’maclist’ file lookup and thus reduce the overhead
              associated with MAC Verification.

              When a new connection arrives from a  ’maclist’  interface,  the
              packet passes through then list of entries for that interface in
              shorewall-maclist 〈shorewall-maclist.html〉 (5). If  there  is  a
              match  then  the  source IP address is added to the ’Recent’ set
              for that interface. Subsequent connection attempts from that  IP
              address  occurring  within $MACLIST_TTL seconds will be accepted
              without having to scan all of the  entries.  After  $MACLIST_TTL
              from  the  first accepted connection request from an IP address,
              the next connection request from that IP address will be checked
              against the entire list.

              If  MACLIST_TTL  is not specified or is specified as empty (e.g,
              MACLIST_TTL="" or is specified as zero  then  ’maclist’  lookups
              will not be cached).

              Previously,  Shorewall  included  a  large  number  of  standard
              actions (AllowPing, AllowFTP, ...).  These  have  been  replaced
              with  parameterized macros. For compatibility, Shorewall can map
              the old names into invocations of the  new  macros  if  you  set
              MAPOLDACTIONS=Yes.  If  this  option is not set or is set to the
              empty  value  (MAPOLDACTIONS="")   then   MAPOLDACTIONS=Yes   is


              MAPOLDACTIONS=Yes  is  not  supported  by  Shorewall-perl.  With
              Shorewall-perl, if MAPOLDACTIONS is not set or  is  set  to  the
              ampty value then MAPOLDACTIONS=No is assumed.

              If  your kernel has a FORWARD chain in the mangle table, you may
              set MARK_IN_FORWARD_CHAIN=Yes to cause the marking specified  in
              the  tcrules  file  to  occur  in  that chain rather than in the
              PREROUTING chain. This permits you to mark inbound traffic based
              on  its destination address when DNAT is in use. To determine if
              your kernel has a FORWARD chain in the  mangle  table,  use  the
              /sbin/shorewall  show  mangle  command;  if  a  FORWARD chain is
              displayed then your kernel will support  this  option.  If  this
              option is not specified or if it is given the empty value (e.g.,
              MARK_IN_FORWARD_CHAIN="")   then   MARK_IN_FORWARD_CHAIN=No   is

       MODULE_SUFFIX=["extension ..."]
              The value of this option determines the possible file extensions
              of kernel modules. The default value is "o gz ko o.gz".

              This parameter specifies the  directory/directories  where  your
              kernel netfilter modules may be found. If you leave the variable
              empty, Shorewall  will  supply  the  value  "/lib/modules/‘uname
              -r‘/kernel/net/ipv4/netfilter" in versions of Shorewall prior to
              3.2.4                  and                  "/lib/modules/‘uname
              -r‘/kernel/net/ipv4/netfilter" in later versions.

              This option will normally be  set  to  ’No’  (the  default).  It
              should be set to ’Yes’ under the following circumstances:

              1.  You  have  an  interface that has parallel zones defined via

              2.  You want to forward multicast packets  to  two  or  more  of
                  those parallel zones.

       In  such  cases,  you  will  configure  a destonly network on each zone
       receiving multicasts.

       The MULTICAST option  is  only  recognized  by  Shorewall-perl  and  is
       ignored by Shorewall-shell.

              The value of this variable determines the number of seconds that
              programs will wait for exclusive access to  the  Shorewall  lock
              file.  After the number of seconds corresponding to the value of
              this variable, programs will assume that  the  last  program  to
              hold the lock died without releasing the lock.

              If not set or set to the empty value, a value of 60 (60 seconds)
              is assumed.

              An appropriate value for  this  parameter  would  be  twice  the
              length  of  time that it takes your firewall system to process a
              shorewall restart command.

              Traditionally, Shorewall has  created  rules  for  the  complete
              matrix of host           groups defined by the zones, interfaces
              and  hosts  files  〈../ScalabilityAndPerformance.html〉   .   Any
              traffic  that didn’t correspond to an element of that matrix was
              rejected in one of the  built-in  chains.  When  the  matrix  is
              sparse, this results in lots of largely useless rules.

              These extra rules can be eliminated by setting OPTIMIZE=1.

              The  OPTIMIZE setting also controls the suppression of redundant
              wildcard rules (those specifying "all" in  the  SOURCE  or  DEST
              column).  A  wildcard rule is considered to be redundant when it
              has the same ACTION and Log Level as the applicable policy.

              Determines the order in which Shorewall searches directories for
              executable files.

              Normally  Shorewall  attempts  to  use  the iptables packet type
              match extension to determine broadcast and multicast packets.

              1.  This can cause a message to appear  during  shorewall  start
                  (modprobe: cant locate module ipt_pkttype).

              2.  Some  users  have  found  problems  with  the  packet  match
                  extension with the result that their firewall log is flooded
                  with messages relating to broadcast packets.

              If  you  are  experiencing  either  of  these  problems, setting
              PKTTYPE=No will prevent Shorewall from trying to use the  packet
              type match extension and to use IP address matching to determine
              which packets are broadcasts or multicasts.


              Eariler generations of Shorewall Lite required that remote  root
              login  via  ssh  be  enabled in order to use the load and reload
              commands.  Beginning with  release  3.9.5,  you  may  define  an
              alternative  means  for accessing the remote firewall system. In
              that release, two new options were added to shorewall.conf:


              The default values for these are as follows:

              RSH_COMMAND: ssh ${root}@${system} ${command}
              RCP_COMMAND: scp ${files} ${root}@${system}:${destination}

              Shell variables that will be set when the commands  are  envoked
              are as follows:

              root  - root user. Normally root but may be overridden using the
              ’-r’ option.
              system - The name/IP address of the remote firewall system.
              command - For RSH_COMMAND, the command to  be  executed  on  the
              firewall system.
              files  -  For RCP_COMMAND, a space-separated list of files to be
              copied to the remote firewall system.
              destination - The directory on the remote system that the  files
              are to be copied into.

              Specifies  the simple name of a file in /var/lib/shorewall to be
              used as the  default  restore  script  in  the  shorewall  save,
              shorewall  restore,  shorewall  forget  and  shorewall  -f start

              During  shorewall  start,  IP  addresses  to  be  added   as   a
              consequence  of  ADD_IP_ALIASES=Yes and ADD_SNAT_ALIASES=Yes are
              quietly deleted when shorewall-nat 〈shorewall-nat.html〉 (5)  and
              shorewall-masq  〈shorewall-masq.html〉 (5) are processed then are
              re-added later. This is done to help ensure that  the  addresses
              can  be  added  with  the  specified  labels  but  can  have the
              undesirable side effect of causing routes to be quietly deleted.
              When  RETAIN_ALIASES  is set to Yes, existing addresses will not
              be  deleted.  Regardless  of  the  setting  of   RETAIN_ALIASES,
              addresses  added  during  shorewall start are still deleted at a
              subsequent shorewall stop or shorewall restart.

              This parameter determines the  level  at  which  packets  logged
              under  the  norfc1918  mechanism are logged. The value must be a
              valid syslog level and if  no  level  is  given,  then  info  is

              Traditionally,  the  RETURN  target  in  the  ’rfc1918’ file has
              caused norfc1918  processing  to  cease  for  a  packet  if  the
              packet’s  source  IP address matches the rule. Thus, if you have
              this entry in shorewall-rfc1918 〈shorewall-rfc1918.html〉 (5):

                  #SUBNETS                 TARGET

              then traffic from to will be accepted  even
              though you also have:

                  #SUBNETS                 TARGET

              Setting  RFC1918_STRICT=Yes  in  shorewall.conf  will cause such
              traffic to be logged and dropped since while the packet’s source
              matches  the  RETURN  rule, the packet’s destination matches the
              ’logdrop’ rule.

              If not specified or specified as empty (e.g., RFC1918_STRICT="")
              then RFC1918_STRICT=No is assumed.


              RFC1918_STRICT=Yes   requires  that  your  kernel  and  iptables
              support ’Connection Tracking’ match.

              If this parameter is given the  value  Yes  or  yes  then  route
              filtering  (anti-spoofing)  is enabled on all network interfaces
              which are brought up while Shorewall is in  the  started  state.
              The default value is no.

              The  value  Keep is only allowed under Shorewall-perl. It causes
              Shorewall to ignore the option. If the option  is  set  to  Yes,
              then  route filtering occurs on all interfaces. If the option is
              set to No, then route filtering is disabled  on  all  interfaces
              except      those      specified     in     shorewall-interfaces
              〈shorewall-interfaces.html〉 (5).

              If SAVE_IPSETS=Yes, then the current  contents  of  your  ipsets
              will  be  saved by the shorewall save command. Regardless of the
              setting of SAVE_IPSETS, if saved ipset  contents  are  available
              then they will be restored by shorewall restore.

              Specifies  the compiler to use to generate firewall scripts when
              both compilers are installed. The value of this  option  can  be
              either  perl  or  shell.  If  both  compilers  are installed and
              SHOREWALL_SHELL  is  not  set,  then  SHOREWALL_SHELL=shell   is

              If        you       add       ’SHOREWALL_COMPILER=perl’       to
              /etc/shorewall/shorewall.conf then by  default,  the  Shorewall-
              perl  compiler  will  be  used  on  the system. If you add it to
              shorewall.conf in a separate directory (such as a Shorewall-lite
              export  directory) then the Shorewall-perl compiler will only be
              used when you compile from that directory.

              If you only install one compiler, it is suggested  that  you  do
              not set SHOREWALL_COMPILER.

              This  setting may be overriden in those commands that invoke the
              compiler  by  using  the  -C  command  option   (see   shorewall
              〈shorewall.html〉 (8)).

              This  option  is used to specify the shell program to be used to
              run the Shorewall compiler and to interpret the compiled script.
              If  not  specified  or  specified  as  a  null value, /bin/sh is
              assumed.  Using a light-weight shell such as  ash  or  dash  can
              significantly improve performance.

              Specifies  the logging level for smurf packets (see the nosmurfs
              option in shorewall-interfaces 〈shorewall-interfaces.html〉 (5)).
              If set to the empty value ( SMURF_LOG_LEVEL="" ) then smurfs are
              not logged.

              Determines if Shorewall is allowed to start.  As  released  from
    , this option is set to No. When set to Yes or yes,
              Shorewall may be started. Used  as  a  guard  against  Shorewall
              being accidentally started before it has been configured.

              This  parameter  should  be  set  to the name of a file that the
              firewall should create if it starts successfully and remove when
              it  stops.  Creating  and removing this file allows Shorewall to
              work with your  distribution’s  initscripts.  For  RedHat,  this
              should  be  set  to  /var/lock/subsys/shorewall. For Debian, the
              value   is   /var/state/shorewall   and   in    LEAF    it    is

              If you say Yes or yes here, Shorewall will use a script that you
              supply to configure traffic shaping. The script  must  be  named
              ’tcstart’ and must be placed in a directory on your CONFIG_PATH.

              If you say No or no then traffic shaping is not enabled.

              If you set TC_ENABLED=Internal or internal or leave  the  option
              empty  then  Shorewall  will  use  its  builtin  traffic  shaper
              (tc4shorewall written by Arne Bernin.

              Normally, Shorewall tries to protect users  from  themselves  by
              preventing  PREROUTING  and OUTPUT tcrules from being applied to
              packets  that  have  been  marked  by  the  ’track’  option   in
              shorewall-providers 〈shorewall-providers.html〉 (5).

              If  you  know  what you are doing, you can set TC_EXPERT=Yes and
              Shorewall will not include these cautionary checks.

              Determines the disposition of TCP packets that fail  the  checks
              enabled   by  the  tcpflags  interface  option  (see  shorewall-
              interfaces 〈shorewall-interfaces.html〉  (5))  and  must  have  a
              value  of  ACCEPT  (accept  the  packet),  REJECT  (send  an RST
              response) or DROP (ignore the packet). If not set or if  set  to
              the    empty   value   (e.g.,   TCP_FLAGS_DISPOSITION="")   then
              TCP_FLAGS_DISPOSITION=DROP is assumed.

              Determines the syslog level for logging packets  that  fail  the
              checks  enabled by the tcpflags interface option. The value must
              be a valid syslogd log level. If you don’t  want  to  log  these
              packets,  set to the empty value (e.g., TCP_FLAGS_LOG_LEVEL="").

              While Shorewall Actions can be very useful, they also require  a
              sizable  amount of code to implement. By setting USE_ACTIONS=No,
              embedded Shorewall installations  can  omit  the  large  library

              USE_ACTIONS=No is not supported by Shorewall-perl.

              Shorewall  has  traditionally  been very noisy (produced lots of
              output). You may set the default level of  verbosity  using  the
              VERBOSITY OPTION.

              Values are:

              0 — Silent. You may make it more verbose using the -v option
              1 — Major progress messages displayed
              2   —  All  progress  messages  displayed  (pre  Shorewall-3.2.0

              If not specified, then 2 is assumed.




       shorewall(8), shorewall-accounting(5), shorewall-actions(5), shorewall-
       blacklist(5),  shorewall-hosts(5),  shorewall-interfaces(5), shorewall-
       ipsec(5),  shorewall-maclist(5),  shorewall-masq(5),  shorewall-nat(5),
       shorewall-netmap(5),      shorewall-params(5),     shorewall-policy(5),
       shorewall-providers(5),        shorewall-proxyarp(5),        shorewall-
       route_rules(5),      shorewall-routestopped(5),     shorewall-rules(5),
       shorewall-tcclasses(5),  shorewall-tcdevices(5),  shorewall-tcrules(5),
       shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)

                               23 November 2007              shorewall.conf(5)