shorewall_code/docs/SharedConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<article>
  <!--$Id$-->

  <articleinfo>
    <title>Shared Shorewall and Shorewall6 Configuration</title>

    <authorgroup>
      <author>
        <firstname>Tom</firstname>

        <surname>Eastep</surname>
      </author>
    </authorgroup>

    <pubdate><?dbtimestamp format="Y/m/d"?></pubdate>

    <copyright>
      <year>2017</year>

      <year>2020</year>

      <holder>Thomas M. Eastep</holder>
    </copyright>

    <legalnotice>
      <para>Permission is granted to copy, distribute and/or modify this
      document under the terms of the GNU Free Documentation License, Version
      1.2 or any later version published by the Free Software Foundation; with
      no Invariant Sections, with no Front-Cover, and with no Back-Cover
      Texts. A copy of the license is included in the section entitled
      <quote><ulink url="GnuCopyright.htm">GNU Free Documentation
      License</ulink></quote>.</para>
    </legalnotice>
  </articleinfo>

  <section>
    <title>Introduction</title>

    <para>Iptables separates management of IPv4 and IPv6 configurations. Each
    address family has its own utility (iptables and ip6tables), and changes
    made to the configuration of one address family do not affect the other.
    While Shorewall also separates the address families in this way, it is
    possible for Shorewall and Shorewall6 to share almost all of the
    configuration files. This article gives an example.</para>

    <caution>
      <para>What is shown here currently works best with Debian and
      derivatives, or when the tarball installer is used and the SPARSE option
      is enabled when running configure[.pl].</para>
    </caution>
  </section>

  <section>
    <title>Environment</title>

    <para>In this example, each address family has two Internet interfaces.
    Both address families share a fast uplink (eth0) that has a single public
    IPv4 address, but can delegate IPv6 subnets to the Shorewall-based router.
    Both address families also have a production uplink. For IPv4, Ethernet is
    used (eth1) and supports the public IPv4 subnet 70.90.191.120/29. For
    IPv6, a Hurricane Electric 6in4 tunnel is used (sit1), which provides the
    public IPv6 subnet 2001:470:b:227::/64. The router also has two bridges. A
    DMZ bridge (br0) provides access to containers running a web server, a
    mail exchanger, and an IMAPS mail access server. The second bridge (br1)
    provides access to a container running irssi under screen, allowing
    constant access to and monitoring of IRC channels.</para>

    <para>The firewall's local ethernet interface (eth2) is connected to a
    Netgear GS108E smart switch with two vlans:</para>

    <itemizedlist>
      <listitem>
        <para>VLAN 1 (eth2.1) is connected to a wireless access point
        supporting both IPv4 (172.20.1.0/24) and IPv6
        (2601:601:a000:16f2::/64).</para>
      </listitem>

      <listitem>
        <para>VLAN 2 (eth2.2) is connected to devices located in my office
        supporting both IPv4 (172.20.1.0/24) and IPv6
        (2601:601:a000:16f2::/64).</para>
      </listitem>
    </itemizedlist>

    <para>The switch's management interface is accessed via eth2
    (192.168.0.0/24).</para>

    <note>
      <para>The GS108E does not currently support restricting the management
      interface to a particular VLAN -- it is accessible from any connected
      host whose IP configuration allows unrouted access to the switch's IP
      address.</para>
    </note>

    <para>Here is a diagram of this installation:</para>

    <graphic fileref="images/Network2020.png"/>

    <para>The boxes in the diagram represent the six shorewall zones (The
    firewall and IPSec vpn zone are not shown).</para>
  </section>

  <section>
    <title>Configuration</title>

    <para>Here are the contents of /etc/shorewall/ and /etc/shorewal6/:</para>

    <programlisting>root@gateway:~# ls -l /etc/shorewall
total 132
-rw-r--r-- 1 root root 1152 May 18 10:51 action.NotSyn
-rw-r--r-- 1 root root  180 Jun 27 09:24 actions
-rw-r--r-- 1 root root   60 May 31 17:55 action.SSHLIMIT
-rw-r--r-- 1 root root   82 Oct  5  2018 arprules
-rw-r--r-- 1 root root  528 May 25 15:39 blrules
-rw-r--r-- 1 root root 1797 Sep 16  2019 capabilities
-rw-r--r-- 1 root root  722 Jul  2 13:49 conntrack
-rw-r--r-- 1 root root  104 Oct 13  2017 hosts
-rw-r--r-- 1 root root 1119 Jul  4 14:02 interfaces
-rw-r--r-- 1 root root  107 Jun 29  2017 isusable
-rw-r--r-- 1 root root  240 Oct 13  2017 macro.FTP
-rw-r--r-- 1 root root  773 Jul  2 15:04 mangle
-rw-r--r-- 1 root root 3108 Jul  3 15:51 params
-rw-r--r-- 1 root root 1108 Jul  3 16:25 policy
-rw-r--r-- 1 root root 2098 Apr 23 17:19 providers
-rw-r--r-- 1 root root  398 Mar 18  2017 proxyarp
-rw-r--r-- 1 root root  726 Oct 24  2018 routes
-rw-r--r-- 1 root root  729 Mar  1 11:08 rtrules
-rw-r--r-- 1 root root 8589 Jul  4 09:34 rules
-rw-r--r-- 1 root root 5503 Jun  5 17:29 shorewall.conf
-rw-r--r-- 1 root root 1090 Jul  2 14:32 snat
-rw-r--r-- 1 root root  180 Jan 30  2018 started
-rw-r--r-- 1 root root  468 Apr 25 14:42 stoppedrules
-rw-r--r-- 1 root root  435 Oct 13  2017 tunnels
-rw-r--r-- 1 root root  978 Jul  3 12:28 zones
root@gateway:~# ls -l /etc/shorewall6
total 12
-rw-r--r-- 1 root root 1786 Sep 16  2019 capabilities
lrwxrwxrwx 1 root root   19 Jul  6  2017 params -&gt; ../shorewall/params
-rw-r--r-- 1 root root 5338 Jun  7 16:40 shorewall6.conf
</programlisting>

    <para>The various configuration files are described in the sections that
    follow. Note that in all cases, these files use the <ulink
    url="/configuration_file_basics.htm#Pairs">alternate format for column
    specification</ulink>.</para>

    <section>
      <title>/usr/share/shorewall/shorewallrc</title>

      <para>The key setting here is SPARSE=Very</para>

      <programlisting>#
# Created by Shorewall Core version 5.0.12-RC1 configure.pl - Sep 25 2016 09:30:55
# rc file: shorewallrc.debian.systemd
#
HOST=debian
PREFIX=/usr
SHAREDIR=${PREFIX}/share
LIBEXECDIR=${PREFIX}/share
PERLLIBDIR=${PREFIX}/share/shorewall
CONFDIR=/etc
SBINDIR=/sbin
MANDIR=${PREFIX}/share/man
INITDIR=
INITSOURCE=init.debian.sh
INITFILE=
AUXINITSOURCE=
AUXINITFILE=
SERVICEDIR=/lib/systemd/system
SERVICEFILE=$PRODUCT.service.debian
SYSCONFFILE=default.debian
SYSCONFDIR=/etc/default
SPARSE=Very
ANNOTATED=
VARLIB=/var/lib
VARDIR=${VARLIB}/$PRODUCT
DEFAULT_PAGER=/usr/bin/less
</programlisting>
    </section>

    <section>
      <title>shorewall.conf and shorewall6.conf</title>

      <para>These are the only files that are not shared between the two
      address families. The key setting is CONFIG_PATH in
      shorewall6.conf:</para>

      <programlisting>CONFIG_PATH="<emphasis role="bold">${CONFDIR}/shorewall6:${CONFDIR}/shorewall:</emphasis>/usr/share/shorewall6:${SHAREDIR}/shorewall"</programlisting>

      <para><filename>/etc/shorewall6/</filename> is only used for processing
      the <filename>params</filename> and <filename>shorewall6.conf</filename>
      files.</para>

      <section>
        <title>shorewall.conf</title>

        <para>The contents of /etc/shorewall/shorewall.conf are as
        follows:</para>

        <programlisting>###############################################################################
#
#  Shorewall Version 5 -- /etc/shorewall/shorewall.conf
#
#  For information about the settings in this file, type "man shorewall.conf"
#
#  Manpage also online at http://www.shorewall.net/manpages/shorewall.conf.html
###############################################################################
#		       S T A R T U P   E N A B L E D
###############################################################################
STARTUP_ENABLED=Yes
###############################################################################
#			     V E R B O S I T Y
###############################################################################
VERBOSITY=1
###############################################################################
#			        P A G E R
###############################################################################
PAGER=pager
###############################################################################
#			     F I R E W A L L
###############################################################################
FIREWALL=
###############################################################################
#			       L O G G I N G
###############################################################################
LOG_LEVEL="NFLOG(0,64,1)"
BLACKLIST_LOG_LEVEL="none"
INVALID_LOG_LEVEL=
LOG_BACKEND=netlink
LOG_MARTIANS=Yes
LOG_VERBOSITY=1
LOG_ZONE=Src
LOGALLNEW=
LOGFILE=/var/log/ulogd/ulogd.syslogemu.log
LOGFORMAT="%s %s"
LOGTAGONLY=Yes
LOGLIMIT="s:5/min"
MACLIST_LOG_LEVEL="$LOG_LEVEL"
RELATED_LOG_LEVEL="$LOG_LEVEL:"
RPFILTER_LOG_LEVEL="$LOG_LEVEL:"
SFILTER_LOG_LEVEL="$LOG_LEVEL"
SMURF_LOG_LEVEL="$LOG_LEVEL"
STARTUP_LOG=/var/log/shorewall-init.log
TCP_FLAGS_LOG_LEVEL="$LOG_LEVEL"
UNTRACKED_LOG_LEVEL=
###############################################################################
#	L O C A T I O N	  O F	F I L E S   A N D   D I R E C T O R I E S
###############################################################################
ARPTABLES=
CONFIG_PATH="/etc/shorewall:/usr/share/shorewall:/usr/share/shorewall/Shorewall"
GEOIPDIR=/usr/share/xt_geoip/LE
IPTABLES=/sbin/iptables
IP=/sbin/ip
IPSET=
LOCKFILE=/var/lib/shorewall/lock
MODULESDIR="+extra/RTPENGINE"
NFACCT=
PATH="/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin"
PERL=/usr/bin/perl
RESTOREFILE=
SHOREWALL_SHELL=/bin/sh
SUBSYSLOCK=
TC=
###############################################################################
#		D E F A U L T   A C T I O N S / M A C R O S
###############################################################################
ACCEPT_DEFAULT="none"
BLACKLIST_DEFAULT="NotSyn(DROP):$LOG_LEVEL"
DROP_DEFAULT="Broadcast(DROP),Multicast(DROP)"
NFQUEUE_DEFAULT="none"
QUEUE_DEFAULT="none"
REJECT_DEFAULT="Broadcast(DROP),Multicast(DROP)"
###############################################################################
#			 R S H / R C P	C O M M A N D S
###############################################################################
RCP_COMMAND='scp ${files} ${root}@${system}:${destination}'
RSH_COMMAND='ssh ${root}@${system} ${command}'
###############################################################################
#			F I R E W A L L	  O P T I O N S
###############################################################################
ACCOUNTING=Yes
ACCOUNTING_TABLE=filter
ADD_IP_ALIASES=No
ADD_SNAT_ALIASES=No
ADMINISABSENTMINDED=Yes
AUTOCOMMENT=Yes
AUTOHELPERS=No
AUTOMAKE=Yes
BALANCE_PROVIDERS=No
BASIC_FILTERS=No
BLACKLIST="NEW,INVALID,UNTRACKED"
CLAMPMSS=No
CLEAR_TC=Yes
COMPLETE=No
DEFER_DNS_RESOLUTION=No
DELETE_THEN_ADD=No
DETECT_DNAT_IPADDRS=No
DISABLE_IPV6=No
DOCKER=No
DONT_LOAD="nf_nat_sip,nf_conntrack_sip,nf_conntrack_h323,nf_nat_h323"
DYNAMIC_BLACKLIST="ipset-only,disconnect,timeout=7200,log,noupdate"
EXPAND_POLICIES=No
EXPORTMODULES=Yes
FASTACCEPT=Yes
FORWARD_CLEAR_MARK=No
HELPERS="ftp,irc"
IGNOREUNKNOWNVARIABLES=No
IMPLICIT_CONTINUE=No
IPSET_WARNINGS=Yes
IP_FORWARDING=Yes
KEEP_RT_TABLES=Yes
MACLIST_TABLE=filter
MACLIST_TTL=60
MANGLE_ENABLED=Yes
MARK_IN_FORWARD_CHAIN=No
MINIUPNPD=No
MULTICAST=No
MUTEX_TIMEOUT=60
NULL_ROUTE_RFC1918=unreachable
OPTIMIZE=All
OPTIMIZE_ACCOUNTING=No
PERL_HASH_SEED=12345
REJECT_ACTION=
RENAME_COMBINED=No
REQUIRE_INTERFACE=No
RESTART=restart
RESTORE_DEFAULT_ROUTE=No
RESTORE_ROUTEMARKS=Yes
RETAIN_ALIASES=No
ROUTE_FILTER=No
SAVE_ARPTABLES=No
SAVE_IPSETS=ipv4
TC_ENABLED=No
TC_EXPERT=No
TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2 2 2"
TRACK_PROVIDERS=Yes
TRACK_RULES=No
USE_DEFAULT_RT=Yes
USE_NFLOG_SIZE=Yes
USE_PHYSICAL_NAMES=Yes
USE_RT_NAMES=Yes
VERBOSE_MESSAGES=No
WARNOLDCAPVERSION=Yes
WORKAROUNDS=No
ZERO_MARKS=No
ZONE2ZONE=-
###############################################################################
#			P A C K E T   D I S P O S I T I O N
###############################################################################
BLACKLIST_DISPOSITION=DROP
INVALID_DISPOSITION=CONTINUE
MACLIST_DISPOSITION=ACCEPT
RELATED_DISPOSITION=REJECT
RPFILTER_DISPOSITION=DROP
SMURF_DISPOSITION=DROP
SFILTER_DISPOSITION=DROP
TCP_FLAGS_DISPOSITION=DROP
UNTRACKED_DISPOSITION=DROP
################################################################################
#			P A C K E T  M A R K  L A Y O U T
################################################################################
TC_BITS=8
PROVIDER_BITS=2
PROVIDER_OFFSET=16
MASK_BITS=8
ZONE_BITS=0</programlisting>
      </section>

      <section>
        <title>shorewall6.conf</title>

        <para>The contents of /etc/shorewall6/shorewall6.conf are:</para>

        <programlisting>###############################################################################
#
#  Shorewall Version 5 -- /etc/shorewall6/shorewall6.conf
#
#  For information about the settings in this file, type "man shorewall6.conf"
#
#  Manpage also online at
#  http://www.shorewall.net/manpages6/shorewall6.conf.html
###############################################################################
#		       S T A R T U P   E N A B L E D
###############################################################################
STARTUP_ENABLED=Yes
###############################################################################
#			     V E R B O S I T Y
###############################################################################
VERBOSITY=1
###############################################################################
#			        P A G E R
###############################################################################
PAGER=pager
###############################################################################
#			     F I R E W A L L
###############################################################################
FIREWALL=
###############################################################################
#			       L O G G I N G
###############################################################################
LOG_LEVEL="NFLOG(0,64,1)"
BLACKLIST_LOG_LEVEL="none"
INVALID_LOG_LEVEL=
LOG_BACKEND=netlink
LOG_VERBOSITY=2
LOG_ZONE=Src
LOGALLNEW=
LOGFILE=/var/log/ulogd/ulogd.syslogemu.log
LOGFORMAT="%s %s"
LOGLIMIT="s:5/min"
LOGTAGONLY=Yes
MACLIST_LOG_LEVEL="$LOG_LEVEL"
RELATED_LOG_LEVEL="$LOG_LEVEL"
RPFILTER_LOG_LEVEL="$LOG_LEVEL"
SFILTER_LOG_LEVEL="$LOG_LEVEL"
SMURF_LOG_LEVEL="$LOG_LEVEL"
STARTUP_LOG=/var/log/shorewall6-init.log
TCP_FLAGS_LOG_LEVEL="$LOG_LEVEL"
UNTRACKED_LOG_LEVEL=
###############################################################################
#	L O C A T I O N	  O F	F I L E S   A N D   D I R E C T O R I E S
###############################################################################
CONFIG_PATH="${CONFDIR}/shorewall6:${CONFDIR}/shorewall:/usr/share/shorewall6:${SHAREDIR}/shorewall"
GEOIPDIR=/usr/share/xt_geoip/LE
IP6TABLES=
IP=
IPSET=
LOCKFILE=
MODULESDIR="+extra/RTPENGINE"
NFACCT=
PERL=/usr/bin/perl
PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin:/usr/local/sbin"
RESTOREFILE=restore
SHOREWALL_SHELL=/bin/sh
SUBSYSLOCK=/var/lock/subsys/shorewall6
TC=
###############################################################################
#		D E F A U L T   A C T I O N S / M A C R O S
###############################################################################
ACCEPT_DEFAULT="none"
BLACKLIST_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP),NotSyn(DROP):$LOG_LEVEL,dropInvalid:$LOG_LEVEL,DropDNSrep:$LOG_LEVEL"
DROP_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP)"
NFQUEUE_DEFAULT="none"
QUEUE_DEFAULT="none"
REJECT_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP)"
###############################################################################
#			 R S H / R C P	C O M M A N D S
###############################################################################
RCP_COMMAND='scp ${files} ${root}@${system}:${destination}'
RSH_COMMAND='ssh ${root}@${system} ${command}'
###############################################################################
#			F I R E W A L L	  O P T I O N S
###############################################################################
ACCOUNTING=Yes
ACCOUNTING_TABLE=mangle
ADMINISABSENTMINDED=Yes
AUTOCOMMENT=Yes
AUTOHELPERS=No
AUTOMAKE=Yes
BALANCE_PROVIDERS=No
BASIC_FILTERS=No
BLACKLIST="NEW,INVALID,UNTRACKED"
CLAMPMSS=Yes
CLEAR_TC=No
COMPLETE=No
DEFER_DNS_RESOLUTION=Yes
DELETE_THEN_ADD=No
DONT_LOAD=
DYNAMIC_BLACKLIST="ipset-only,disconnect,timeout=7200,log,noupdate"
EXPAND_POLICIES=No
EXPORTMODULES=Yes
FASTACCEPT=Yes
FORWARD_CLEAR_MARK=No
HELPERS=ftp
IGNOREUNKNOWNVARIABLES=No
IMPLICIT_CONTINUE=No
IPSET_WARNINGS=Yes
IP_FORWARDING=Keep
KEEP_RT_TABLES=Yes
MACLIST_TABLE=filter
MACLIST_TTL=
MANGLE_ENABLED=Yes
MARK_IN_FORWARD_CHAIN=No
MINIUPNPD=No
MUTEX_TIMEOUT=60
OPTIMIZE=All
OPTIMIZE_ACCOUNTING=No
PERL_HASH_SEED=0
REJECT_ACTION=
RENAME_COMBINED=No
REQUIRE_INTERFACE=No
RESTART=restart
RESTORE_DEFAULT_ROUTE=No
RESTORE_ROUTEMARKS=Yes
SAVE_IPSETS=No
TC_ENABLED=Shared
TC_EXPERT=No
TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2 2 2"
TRACK_PROVIDERS=Yes
TRACK_RULES=No
USE_DEFAULT_RT=Yes
USE_NFLOG_SIZE=Yes
USE_PHYSICAL_NAMES=Yes
USE_RT_NAMES=No
VERBOSE_MESSAGES=No
WARNOLDCAPVERSION=Yes
WORKAROUNDS=No
ZERO_MARKS=No
ZONE2ZONE=-
###############################################################################
#			P A C K E T   D I S P O S I T I O N
###############################################################################
BLACKLIST_DISPOSITION=DROP
INVALID_DISPOSITION=CONTINUE
MACLIST_DISPOSITION=REJECT
RELATED_DISPOSITION=REJECT
SFILTER_DISPOSITION=DROP
RPFILTER_DISPOSITION=DROP
SMURF_DISPOSITION=DROP
TCP_FLAGS_DISPOSITION=DROP
UNTRACKED_DISPOSITION=DROP
################################################################################
#			P A C K E T  M A R K  L A Y O U T
################################################################################
TC_BITS=8
PROVIDER_BITS=2
PROVIDER_OFFSET=8
MASK_BITS=8
ZONE_BITS=0
</programlisting>
      </section>
    </section>

    <section>
      <title>params</title>

      <para>Because addresses and interfaces are different between the two
      address families, they cannot be hard-coded in the configuration files.
      <filename>/etc/shorewall/params</filename> is used to set shell
      variables whose contents will vary between Shorewall and Shorewall6. In
      the <filename>params</filename> file and in run-time extension files,
      the shell variable <emphasis role="bold">g_family</emphasis> can be used
      to determine which address family to use; if IPv4, then $g_family will
      expand to 4 and if IPv6, $g_family will expand to 6.</para>

      <para>The contents of /etc/shorewall/params is as follows:</para>

      <programlisting>#
# Set compile-time variables depending on the address family
#
if [ $g_family = 4 ]; then
    #
    # IPv4 compilation
    #
    FALLBACK=Yes           # Make FAST_IF the primary and PROD_IF the fallback interface
			   # See /etc/shorewall/providers
    STATISTICAL=	   # Use statistical load balancing
    LISTS=70.90.191.124	   # IP address of lists.shorewall.net (MX)
    MAIL=70.90.191.122	   # IP address of mail.shorewall.net  (IMAPS)
    SERVER=70.90.191.125   # IP address of www.shorewall.org
    IRSSIEXT=10.2.10.2 	   # External address of irssi.shorewall.net
    IRSSIINT=172.20.2.44   # Internal IP address of irssi.shorewall.net
    PROXY=Yes		   # Use TPROXY for local web access
    ALL=0.0.0.0/0	   # Entire address space
    LOC_ADDR=172.20.1.253  # IP address of the local LAN interface
    FAST_GATEWAY=10.2.10.1 # Default gateway through the IF_FAST interface
    FAST_MARK=0x20000	   # Multi-ISP mark setting for IF_FAST
    IPSECMSS=1460
    DBL_SET=SW_DBL4
    #
    # Interface Options
    #
    LOC_OPTIONS=dhcp,ignore=1,wait=5,routefilter,tcpflags=0,nodbl,physical=eth2.2
    WLAN_OPTIONS=dhcp,ignore=1,wait=5,routefilter,tcpflags=0,nodbl,physical=eth2.1
    FAST_OPTIONS=optional,dhcp,tcpflags,nosmurfs,sourceroute=0,arp_ignore=1,proxyarp=0,nosmurfs,rpfilter,physical=eth0
    PROD_OPTIONS=optional,dhcp,tcpflags,nosmurfs,sourceroute=0,arp_ignore=1,proxyarp=0,nosmurfs,rpfilter,physical=eth1
    DMZ_OPTIONS=routeback,proxyarp=1,required,wait=30,nets=70.90.191.120/29,nodbl,physical=br0
    IRC_OPTIONS=routeback,proxyarp=1,required,wait=30,nets=172.20.2.0/24,dhcp,nodbl,physical=br1
    SWCH_OPTIONS=dhcp,tcpflags=0,nodbl,physical=eth2
else
    #
    # IPv6 compilation
    #
    FALLBACK=Yes			      # Make FAST_IF the primary and PROD_IF the fallback interface
					      # See /etc/shorewall/providers
    STATISTICAL=No			      # Don't use statistical load balancing
    LISTS=[2001:470:b:227::42]		      # IP address of lists.shorewall.net (MX and HTTPS)
    MAIL=[2001:470:b:227::45]		      # IP address of mail.shorewall.net  (IMAPS and HTTPS)
    SERVER=[2001:470:b:227::43]		      # IP address of server.shorewall.net(FTP)
    IRSSI=[2601:601:a000:16f1::]/64	      # IP address of irssi.shorewall.net
    PROXY=Yes				      # Use TPROXY for local web access
    ALL=[::]/0				      # Entire address space
    LOC_ADDR=[2601:601:a000:16f0::1]	      # IP address of the local LAN interface
    FAST_GATEWAY=2601:601:a000:1600:22e5:2aff:feb7:f2cf
    FAST_MARK=0x100			      # Multi-ISP mark setting for IF_FAST
    IPSECMSS=1440
    DBL_SET=SW_DBL6
    #
    # Interface Options
    #
    PROD_OPTIONS=forward=1,optional,rpfilter,routeback,physical=sit1
    FAST_OPTIONS=forward=1,optional,dhcp,rpfilter,physical=eth0
    LOC_OPTIONS=forward=1,nodbl,routeback,physical=eth2.2
    DMZ_OPTIONS=routeback,forward=1,required,wait=30,nodbl,physical=br0
    IRC_OPTIONS=routeback,forward=1,required,wait=30,nodbl,physical=br1
    WLAN_OPTIONS=forward=1,nodbl,routeback,physical=eth2.1
fi</programlisting>
    </section>

    <section>
      <title>zones</title>

      <para>Here is the /etc/shorewall/zones file:</para>

      <programlisting>#ZONE	TYPE	OPTIONS			IN			OUT
#					OPTIONS			OPTIONS

#
# By using the 'ip' type, both Shorewall and Shorewall6 can share this file
#

fw	{ TYPE=firewall }
net	{ TYPE=ip }
loc	{ TYPE=ip }
dmz	{ TYPE=ip }
apps	{ TYPE=ip }
vpn	{ TYPE=ipsec, OPTIONS=mode=tunnel,proto=esp,mss=$IPSECMSS }
wlan    { TYPE=ip }
?if __IPV4
swch	{ TYPE=local }
?endif</programlisting>
    </section>

    <section>
      <title>interfaces</title>

      <para>/etc/shorewall/interfaces makes heavy use of variables set in
      /etc/shorewall/params:</para>

      <programlisting>?FORMAT 2
###############################################################################
#ZONE	INTERFACE	OPTIONS

#
# The two address families use different production interfaces and different 
#
# LOC_IF is the local LAN for both families
# FAST_IF is a Comcast IPv6 beta uplink which is used for internet access from the local lan for both families
# PROD_IF is the interface used by shorewall.org servers
#     For IPv4, it is eth1
#     For IPv6, it is sit1 (Hurricane Electric 6in4 link)
# DMZ_IF is a bridge to the production containers
# IRC_IF is a bridge to a container that currently runs irssi under screen
# WLAN_IF is a vlan interface that connects to the wireless networks
# SWCH_IF is the vlan trunk interface used for switch management

loc  { INTERFACE=LOC_IF,  OPTIONS=$LOC_OPTIONS }
wlan { INTERFACE=WLAN_IF, OPTIONS=$WLAN_OPTIONS }
net  { INTERFACE=FAST_IF, OPTIONS=$FAST_OPTIONS }
net  { INTERFACE=PROD_IF, OPTIONS=$PROD_OPTIONS }
dmz  { INTERFACE=DMZ_IF,  OPTIONS=$DMZ_OPTIONS }
apps { INTERFACE=IRC_IF,  OPTIONS=$IRC_OPTIONS }
?if __IPV4
swch { INTERFACE=SWCH_IF, OPTIONS=$SWCH_OPTIONS }
?endif</programlisting>
    </section>

    <section>
      <title>hosts</title>

      <para>/etc/shorewall/hosts is used to define the vpn zone:</para>

      <programlisting>##ZONE		HOSTS				OPTIONS
vpn { HOSTS=PROD_IF:$ALL }
vpn { HOSTS=FAST_IF:$ALL }
vpn { HOSTS=LOC_IF:$ALL }</programlisting>
    </section>

    <section>
      <title>policy</title>

      <para>The same set of policies apply to both address families:</para>

      <programlisting>SOURCE	       DEST		 POLICY									  LOGLEVEL	      RATE

$FW	      { DEST=dmz,net,	 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }

?if __IPV4
$FW	      { DEST=all,	 POLICY=ACCEPT:Broadcast(ACCEPT),Multicast(ACCEPT),			  LOGLEVEL=$LOG_LEVEL }
?else
$FW	      { DEST=all,	 POLICY=ACCEPT:AllowICMPs,Broadcast(ACCEPT),Multicast(ACCEPT)		  LOGLEVEL=$LOG_LEVEL }
?endif

loc,apps,wlan { DEST=net,	 POLICY=ACCEPT }
loc,vpn,apps  { DEST=loc,vpn,apps POLICY=ACCEPT }
loc	      { DEST=fw,		 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }

?if __IPV4
net	      { DEST=net,	 POLICY=NONE }
?else
net	      { DEST=net,	 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }
?endif
net	      { DEST=fw,	 POLICY=BLACKLIST:+Broadcast(DROP),Multicast(DROP),DropDNSrep:$LOG_LEVEL, LOGLEVEL=$LOG_LEVEL, RATE=8/sec:30 }
net	      { DEST=all,	 POLICY=BLACKLIST:+DropDNSrep:$LOG_LEVEL,				  LOGLEVEL=$LOG_LEVEL, RATE=8/sec:30 }

dmz	      { DEST=fw, 	 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }
dmz	      { DEST=dmz, 	 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }
all	      { DEST=all,	 POLICY=REJECT,								  LOGLEVEL=$LOG_LEVEL }</programlisting>
    </section>

    <section>
      <title>providers</title>

      <para>The providers file is set up to allow for three different
      configurations:</para>

      <orderedlist>
        <listitem>
          <para>FALLBACK -- FAST_IF is the primary interface and PROD_IF is
          the fallback</para>
        </listitem>

        <listitem>
          <para>STATISTICAL -- Statistical load balancing between FAST_IF and
          PROD_IF</para>
        </listitem>

        <listitem>
          <para>IPv4 only -- balance between FAST_IF and PROD_IF</para>
        </listitem>
      </orderedlist>

      <programlisting>#NAME		NUMBER   MARK    DUPLICATE  INTERFACE	GATEWAY         OPTIONS               COPY

#
# This could be cleaned up a bit, but I'm leaving it as is for now
#
#   - The two address families use different fw mark geometry
#   - The two address families use different fallback interfaces
#   - The 'balance' option doesn't work as expected in IPv6 so I have no balance configuration for Shorewall6
#   - IPv4 uses the 'loose' option on PROD_IF
#
?if $FALLBACK
    # FAST_IF is primary, PROD_IF is fallback
    #
    ?if $VERBOSITY &gt; 0
        ?info Compiling with FALLBACK
    ?endif
    IPv6Beta	    { NUMBER=1, MARK=$FAST_MARK, INTERFACE=FAST_IF, GATEWAY=$FAST_GATEWAY, OPTIONS=loose,primary,persistent,noautosrc }
    ?if __IPV4
	ComcastB    { NUMBER=4, MARK=0x10000,	 INTERFACE=PROD_IF, GATEWAY=10.1.10.1, OPTIONS=loose,fallback,persistent }
    ?else    
	HE	    { NUMBER=2, MARK=0x200,	 INTERFACE=PROD_IF, OPTIONS=fallback,persistent }
    ?endif
?elsif $STATISTICAL
    # Statistically balance traffic between FAST_IF and PROD_IF
    ?if $VERBOSITY &gt; 0
        ?info Compiling with STATISTICAL
    ?endif
    ?if __IPV4
    	IPv6Beta    { NUMBER=1, MARK=0x20000, INTERFACE=FAST_IF, GATEWAY=$FAST_GATEWAY, OPTIONS=loose,load=0.66666667,primary,persistent }
	ComcastB    { NUMBER=4, MARK=0x10000, INTERFACE=PROD_IF, GATEWAY=10.1.10.1, OPTIONS=loose,load=0.33333333,fallback,persistent }
    ?else
	HE	    { NUMBER=2, MARK=0x200,   INTERFACE=PROD_IF,                        OPTIONS=track,load=0.33333333,persistent }
    ?endif
?else
    ?if $VERBOSITY &gt; 0
        ?info Compiling with BALANCE
    ?endif
    IPv6Beta	 { NUMBER=1, MARK=$FAST_MARK, INTERFACE=FAST_IF, GATEWAY=$FAST_GATEWAY, OPTIONS=track,balance=2,loose,persistent }
    ?if __IPV4
	ComcastB { NUMBER=4, MARK=0x10000,    INTERFACE=PROD_IF, GATEWAY=10.1.10.1,     OPTIONS=nohostroute,loose,balance,persistent }
    ?else
        ?warning No BALANCE IPv6 configuration
	HE	 { NUMBER=2, MARK=0x200,   INTERFACE=PROD_IF,			     OPTIONS=fallback,persistent }
    ?endif    
?endif

Tproxy   { NUMBER=3, INTERFACE=lo, OPTIONS=tproxy }</programlisting>
    </section>

    <section>
      <title>rtrules</title>

      <para>The routing rules are quite dependent on the address
      family:</para>

      <programlisting>#SOURCE             DEST             PROVIDER  PRIORITY

#
# This file ensures that the DMZ is routed out of the IF_PROD interface
# and that the IPv6 subnets delegated by the Beta router are routed out
# of the IF_FAST interface.
#
?if __IPV4
    { SOURCE=70.90.191.121,70.90.191.123,10.1.10.1 PROVIDER=ComcastB, PRIORITY=1000! }
    { SOURCE=&amp;FAST_IF,	              	  	   PROVIDER=IPv6Beta, PRIORITY=1000! }
    { SOURCE=br0,	     		  	   PROVIDER=ComcastB, PRIORITY=11000 }
?else
    { SOURCE=2601:601:a000:1600::/64		   PROVIDER=IPv6Beta, PRIORITY=1000! }
    { SOURCE=2001:470:B:227::/64,         	   PROVIDER=HE,	      PRIORITY=1000! }
    { SOURCE=2601:601:a000:16f0::/60	  	   PROVIDER=IPv6Beta, PRIORITY=11000 }
?endif</programlisting>
    </section>

    <section>
      <title>routes</title>

      <para>This file is used only for IPv6:</para>

      <programlisting>#PROVIDER		DEST			GATEWAY		DEVICE	OPTIONS
?if __IPV6
    #
    # In my version of FOOLSM (1.0.10), the 'sourceip' option doesn't work.
    # As a result, routing rules that specify the source IPv6 address are
    # not effective in routing the 'ping' request packets out of FAST_IF.
    # The following route solves that problem.
    #
    { PROVIDER=main, DEST=2001:558:4082:d3::1/128, GATEWAY=$FAST_GATEWAY, DEVICE=FAST_IF, OPTIONS=persistent }
?endif</programlisting>
    </section>

    <section>
      <title>actions</title>

      <para>/etc/shorewall/actions defines a single action:</para>

      <programlisting>#ACTION      OPTIONS            COMMENT
SSHLIMIT     proto=tcp,\	# Blacklist overzealous SSHers
	     dport=ssh</programlisting>

      <para>/etc/shorewall/action.SSHLIMIT:</para>

      <programlisting>ACCEPT { RATE=s:3/min:3 }
BLACKLIST:$LOG_LEVEL:net_SSHLIMIT</programlisting>
    </section>

    <section>
      <title>Macros</title>

      <para>/etc/shorewall/macro.FTP:</para>

      <programlisting>###############################################################################
#ACTION	SOURCE	DEST	PROTO	DPORT	SPORT	ORIGDEST	RATE	USER
PARAM	-	-	tcp	21
</programlisting>

      <para>This is just the normal Shorewall FTP macro without the helper
      logic -- we take care of that in the conntrack file below.</para>
    </section>

    <section>
      <title>conntrack</title>

      <para>In addition to invoking the FTP helper on TCP port 21, this file
      notracks some IPv4 traffic:</para>

      <programlisting>?FORMAT 3
######################################################################################################
#ACTION			SOURCE		DEST		PROTO	DPORT		SPORT	USER	SWITCH

CT:helper:ftp:P	 { PROTO=tcp, DPORT=21 }
CT:helper:ftp:O  { PROTO=tcp, DPORT=21 }

?if __IPV4
    #
    # Don't track IPv4 broadcasts
    #
    NOTRACK:P       { SOURCE=LOC_IF, DEST=172.20.1.255,   PROTO=udp }
    NOTRACK:P       { DEST=255.255.255.255, 	          PROTO=udp }
    NOTRACK:O       { DEST=255.255.255.255, 	          PROTO=udp }
    NOTRACK:O       { DEST=LOC_IF:172.20.0.255,    	  PROTO=udp }
    NOTRACK:O       { DEST=LOC_IF:172.20.1.255,    	  PROTO=udp }
    NOTRACK:O       { DEST=PROD_IF:70.90.191.127,         PROTO=udp }
?endif</programlisting>
    </section>

    <section>
      <title>rules</title>

      <para>/etc/shorewall/rules has only a couple of rules that are
      conditional based on address family:</para>

      <programlisting>##############################################################################################################################################################
#ACTION		SOURCE		DEST		PROTO	DPORT	SPORT	ORIGDEST	RATE	USER	MARK	CONNLIMIT	TIME	HEADERS	SWITCH	HELPER

?SECTION ALL

Ping(ACCEPT)	{ SOURCE=net, DEST=all, RATE=d:ping(1024,65536):2/sec:10 }
Trcrt(ACCEPT)	{ SOURCE=net, DEST=all, RATE=d:ping(1024,65536):2/sec:10 }

?SECTION ESTABLISHED

?SECTION RELATED

ACCEPT		{ SOURCE=all, DEST=dmz:$SERVER, PROTO=tcp,  DPORT=61001:62000,  helper=ftp }
ACCEPT		{ SOURCE=dmz, DEST=all,		PROTO=tcp,  helper=ftp }
ACCEPT		{ SOURCE=all, DEST=net,		PROTO=tcp,  helper=ftp }
ACCEPT		{ SOURCE=$FW, DEST=loc,		PROTO=tcp,  helper=ftp }
ACCEPT		{ SOURCE=loc, DEST=$FW,		PROTO=tcp,  helper=ftp }
ACCEPT		{ SOURCE=all, DEST=all,		PROTO=icmp }
RST(ACCEPT)	{ SOURCE=all, DEST=all }
ACCEPT		{ SOURCE=dmz, DEST=dmz }
ACCEPT		{ SOURCE=$FW, DEST=$FW,         PROTO=icmp }

?SECTION INVALID

RST(ACCEPT)	{ SOURCE=all, DEST=all }
FIN(ACCEPT)	{ SOURCE=all, DEST=all }
DROP		{ SOURCE=net, DEST=all }

?SECTION UNTRACKED

?if __IPV4
Broadcast(ACCEPT) { SOURCE=all, DEST=$FW }
ACCEPT		  { SOURCE=all, DEST=$FW, PROTO=udp }
CONTINUE	  { SOURCE=loc, DEST=$FW }
CONTINUE	  { SOURCE=$FW, DEST=all }
?endif

?SECTION NEW

######################################################################################################
# Stop certain outgoing traffic to the net
#
REJECT:$LOG_LEVEL { SOURCE=loc,vpn,apps DEST=net, PROTO=tcp, DPORT=25 }		#Stop direct loc-&gt;net SMTP (Comcast uses submission).
#REJECT:$LOG_LEVEL { SOURCE=loc,vpn,apps DEST=net, PROTO=udp, DPORT=1025:1031 }	#MS Messaging

REJECT		{ SOURCE=all!dmz,apps, DEST=net, PROTO=tcp, DPORT=137,445, comment="Stop NETBIOS Crap" }
REJECT		{ SOURCE=all!dmz,apps, DEST=net, PROTO=udp, DPORT=137:139, comment="Stop NETBIOS Crap" }

REJECT		{ SOURCE=all, DEST=net, PROTO=tcp, DPORT=3333, comment="Disallow port 3333" }

REJECT		{ SOURCE=all, DEST=net, PROTO=udp, DPORT=3544, comment="Stop Teredo" }

?if __IPV6
DROP		{ SOURCE=net:PROD_IF, DEST=net:PROD_IF }
?endif

?COMMENT

######################################################################################################
# SACK
#
DROP:$LOG_LEVEL	 { SOURCE=net, DEST=all } ;;+ -p tcp -m tcpmss --mss 1:535

######################################################################################################
# 6in4
#
?if __IPV4
    ACCEPT		    { SOURCE=net:216.218.226.238, DEST=$FW, PROTO=41 }
    ACCEPT		    { SOURCE=$FW, DEST=net:216.218.226.238, PROTO=41 }
?endif
######################################################################################################
# Ping
#
Ping(ACCEPT)	  { SOURCE=all!net, DEST=all }
Ping(ACCEPT)	  { SOURCE=dmz, DEST=dmz }
?if __IPV4
Ping(ACCEPT)	  { source=$FW, DEST=swch }
?endif
######################################################################################################
# Logging
#
Syslog(ACCEPT)	  { SOURCE=dmz, DEST=$FW }
######################################################################################################
# SSH
#
SSH(DROP)	  { SOURCE=net, DEST=dmz:$SERVER }
SSHLIMIT	  { SOURCE=net, DEST=all }
?if __IPV4
SSH(ACCEPT)	  { SOURCE=all+!swch, DEST=all+ }
SSH(DNAT-)	  { SOURCE=net,              DEST=172.20.2.44, PROTO=tcp, DPORT=ssh, ORIGDEST=70.90.191.123 }
?else
SSH(ACCEPT)	  { SOURCE=all+, DEST=all+ }
?endif
######################################################################################################
# DNS
#
DNS(ACCEPT)	  { SOURCE=loc,dmz,vpn,apps,wlan, DEST=$FW }
DNS(ACCEPT)	  { SOURCE=$FW,  DEST=net }
?if $TEST
DNS(REDIRECT)	  loc		53	 -	53	-	!&amp;LOC_IF
DNS(REDIRECT)	  fw		53	 -	53	-	!::1
?endif
DropDNSrep        { SOURCE=net, DEST=all }
######################################################################################################
# Traceroute
#
Trcrt(ACCEPT)	  { SOURCE=all, DEST=net }
Trcrt(ACCEPT)	  { SOURCE=net, DEST=$FW,dmz }
######################################################################################################
# Email
#
SMTP(ACCEPT)	   { SOURCE=net,$FW, DEST=dmz:$LISTS }
SMTP(ACCEPT)	   { SOURCE=dmz:$LISTS, DEST=net:PROD_IF }
SMTP(ACCEPT)	   { SOURCE=dmz, DEST=dmz:$LISTS }
SMTP(REJECT)	   { SOURCE=dmz:$LISTS, DEST=net }
IMAPS(ACCEPT)  	   { SOURCE=all, DEST=dmz:$MAIL }
Submission(ACCEPT) { SOURCE=all, DEST=dmz:$LISTS }
SMTPS(ACCEPT) 	   { SOURCE=all, DEST=dmz:$LISTS }
IMAP(REJECT)	   { SOURCE=net, DEST=all }
######################################################################################################
# NTP
#
NTP(ACCEPT)	   { SOURCE=all, DEST=net }
######################################################################################################
# Squid
ACCEPT { SOURCE=loc,vpn,wlan, DEST=$FW, PROTO=tcp, DPORT=3128 } 
######################################################################################################
# HTTP/HTTPS
#
Web(ACCEPT)	   { SOURCE=loc,vpn,wlan DEST=$FW }
Web(ACCEPT)	   { SOURCE=$FW, DEST=net, USER=proxy }
Web(DROP)	   { SOURCE=net, DEST=fw, PROTO=tcp, comment="Do not blacklist web crawlers" }
HTTP(ACCEPT)	   { SOURCE=net,loc,vpn,wlan,$FW DEST=dmz:$SERVER,$LISTS,$MAIL }
HTTPS(ACCEPT)	   { SOURCE=net,loc,vpn,wlan,$FW DEST=dmz:$SERVER,$LISTS,$MAIL }
Web(ACCEPT)	   { SOURCE=dmz,apps,loc,wlan, DEST=net,$FW }
Web(ACCEPT)	   { SOURCE=$FW, DEST=net, USER=root }
Web(ACCEPT)	   { SOURCE=$FW, DEST=net, USER=teastep }
?if __IPV4
Web(ACCEPT)	   { SOURCE=$FW, DEST=swch, USER=teastep }
?endif
Web(ACCEPT)	   { SOURCE=$FW, DEST=net, USER=_apt }
######################################################################################################
# FTP
#
FTP(ACCEPT)	   { SOURCE=dmz,               DEST=net }
FTP(ACCEPT)	   { SOURCE=$FW,               DEST=net, USER=root }
FTP(ACCEPT)	   { SOURCE=all,               DEST=dmz:$SERVER }
#
# Some FTP clients seem prone to sending the PORT command split over two packets.
# This prevents the FTP connection tracking code from processing the command and setting
# up the proper expectation.
#
# The following rule allows active FTP to work in these cases
# but logs the connection so I can keep an eye on this potential security hole.
#
ACCEPT:$LOG_LEVEL  { SOURCE=dmz, DEST=net, PROTO=tcp, DPORT=1024:, SPORT=20 }
######################################################################################################
# Git
#
Git(ACCEPT)        { source=all, DEST=dmz:$SERVER }
######################################################################################################
# whois
#
Whois(ACCEPT)	   { SOURCE=all, DEST=net }
######################################################################################################
# SMB
#
SMBBI(ACCEPT)	    { SOURCE=loc,wlan, DEST=$FW }
SMBBI(ACCEPT)	    { SOURCE=vpn,      DEST=$FW }
######################################################################################################
# IRC
#
SetEvent(IRC)	                      { SOURCE=loc,apps,wlan, DEST=net, PROTO=tcp, DPORT=6667 }
IfEvent(IRC,ACCEPT,10,1,dst,reset)    { SOURCE=net, DEST=loc,apps,wlan, PROTO=tcp, DPORT=113 }
######################################################################################################
# AUTH
Auth(REJECT)	{ SOURCE=net, DEST=all }
######################################################################################################
# IPSEC
#
?if __IPV4
DNAT		{ SOURCE=loc,net,wlan, DEST=apps:172.20.2.44, PROTO=udp, DPORT=500,4500, ORIGDEST=70.90.191.123 }
?else
ACCEPT		{ SOURCE=loc,net,wlan, DEST=apps, PROTO=udp, DPORT=500,4500 }
ACCEPT		{ SOURCE=loc,net,wlan, DEST=apps, PROTO=esp }
?endif
ACCEPT		{ SOURCE=$FW,     DEST=net,  PROTO=udp, SPORT=4500 }
######################################################################################################
# VNC
ACCEPT		{ SOURCE=loc,	  DEST=$FW,	  PROTO=tcp,		DPORT=5900 }
######################################################################################################
# FIN &amp; RST
RST(ACCEPT)	{ SOURCE=all, DEST=all }
FIN(ACCEPT)	{ SOURCE=all, DEST=all }
######################################################################################################
# Multicast
?if __IPV4
Multicast(ACCEPT) { SOURCE=all, DEST=$FW }
?endif
######################################################################################################
?if __IPV4
ACCEPT		{ SOURCE=fw, DEST=all, PROTO=icmp, DPORT=host-unreachable }
?endif</programlisting>
    </section>

    <section>
      <title>mangle</title>

      <para>Note that TPROXY can be enabled/disabled via a shell variable
      setting in /etc/shorewall/params:</para>

      <programlisting>#ACTION		SOURCE		DEST		PROTO	DPORT	SPORT	USER	TEST	LENGTH	TOS	CONNBYTES	HELPER	PROBABILITY	DSCP

?if $VERSION &gt;= 50109
TCPMSS(pmtu,none) { PROTO=tcp }
?endif

?if __IPV4
    #
    # I've had a checksum issue with certain IPv4 UDP packets
    #
    CHECKSUM:T { DEST=FAST_IF, PROTO=udp }
    CHECKSUM:T { DEST=DMZ_IF,  PROTO=udp }
?endif

?if $PROXY
    #
    # Use TPROXY for web access from the local LAN
    #
    DIVERT:R { PROTO=tcp, SPORT=80 }
    DIVERT:R { PROTO=tcp, DPORT=80 }
    TPROXY(3129,$LOC_ADDR) { SOURCE=LOC_IF,  PROTO=tcp, DPORT=80 }
    TPROXY(3129,$LOC_ADDR) { SOURCE=WLAN_IF, PROTO=tcp, DPORT=80 }
#    DIVERT:R { PROTO=tcp, SPORT=443 }
#    DIVERT:R { PROTO=tcp, DPORT=443 }
#    TPROXY(3129,$LOC_ADDR) { SOURCE=LOC_IF, PROTO=tcp, DPORT=443 }
?endif</programlisting>
    </section>

    <section>
      <title>snat</title>

      <para>NAT entries are quite dependent on the address family:</para>

      <programlisting>#ACTION         SOURCE			DEST            PROTO   PORT   IPSEC  MARK   USER    SWITCH  ORIGDEST   PROBABILITY

?if __IPV4
    MASQUERADE			{ SOURCE=172.20.0.0/22,               DEST=FAST_IF }
    MASQUERADE			{ SOURCE=70.90.191.120/29, 	      DEST=FAST_IF }
    SNAT(70.90.191.121) 	{ SOURCE=!70.90.191.120/29,	      DEST=PROD_IF,  PROBABILITY=0.50, COMMENT="Masquerade Local Network" }
    SNAT(70.90.191.123) 	{ SOURCE=!70.90.191.120/29,	      DEST=PROD_IF,                    COMMENT="Masquerade Local Network" }
    SNAT(172.20.1.253)  	{ SOURCE=!172.20.1.0/24, 	      DEST=LOC_IF:172.20.1.100 }
?else
    SNAT(&amp;PROD_IF)		{ SOURCE=2601:601:a000:16f0::/60,               DEST=PROD_IF }
    SNAT(&amp;FAST_IF)		{ SOURCE=2001:470:b:227::/64,2001:470:a:227::2,	DEST=FAST_IF }
?endif</programlisting>
    </section>

    <section>
      <title>tunnels</title>

      <para>Both address families define IPsec tunnels:</para>

      <programlisting>#TYPE			ZONE		GATEWAY			GATEWAY_ZONE
ipsecnat {ZONE=net,  GATEWAY=$ALL, GATEWAY_ZONE=vpn }
ipsecnat {ZONE=loc,  GATEWAY=$ALL, GATEWAY_ZONE=vpn }
</programlisting>
    </section>

    <section>
      <title>proxyarp</title>

      <programlisting>#ADDRESS	INTERFACE	EXTERNAL	HAVEROUTE	PERSISTENT

70.90.191.122 { INTERFACE=br0, EXTERNAL=eth1, HAVEROUTE=yes, PERSISTENT=no }
</programlisting>
    </section>

    <section>
      <title>isuable</title>

      <para>This is just the standard Shorewall isusable extension
      script:</para>

      <programlisting>local status
status=0

[ -f ${VARDIR}/${1}.status ] &amp;&amp; status=$(cat ${VARDIR}/${1}.status)

return $status
</programlisting>
    </section>

    <section>
      <title>started</title>

      <para>/etc/shorewall/started only does something in the IPv4
      configuration, although it gets compiled into both scripts:</para>

      <programlisting>if [ $g_family = 4 ]; then
    qt $IP -4 route replace 70.90.191.122 dev br0
    qt $IP -4 route replace 70.90.191.124 dev br0
    qt $IP -4 route replace 70.90.191.125 dev br0
fi
</programlisting>
    </section>

    <section>
      <title>stoppedrules</title>

      <para>/etc/shorewall/stoppedrules allow SSH connections into the
      firewall system when Shorewall[6] is in the stopped state.</para>

      <programlisting>#ACTION		SOURCE			DEST		PROTO	DPORT	SPORT
ACCEPT		-			$FW		tcp	22
</programlisting>
    </section>
  </section>
</article>