Provided by: shorewall_4.4.26.1-1_all bug

NAME

       rules - Shorewall rules file

SYNOPSIS

       /etc/shorewall/rules

DESCRIPTION

       Entries in this file govern connection establishment by defining exceptions to the
       policies layed out in shorewall-policy[1](5). By default, subsequent requests and
       responses are automatically allowed using connection tracking. For any particular
       (source,dest) pair of zones, the rules are evaluated in the order in which they appear in
       this file and the first terminating match is the one that determines the disposition of
       the request. All rules are terminating except LOG and COUNT rules.

           Warning
           If you masquerade or use SNAT from a local system to the internet, you cannot use an
           ACCEPT rule to allow traffic from the internet to that system. You must use a DNAT
           rule instead.

       The rules file is divided into sections. Each section is introduced by a "Section Header"
       which is a line beginning with SECTION and followed by the section name.

       Sections are as follows and must appear in the order listed:

       BLACKLIST
           This section was added in Shorewall 4.4.25.

           Rules in this section are applied depending on the setting of BLACKLISTNEWONLY in
           shorewall.conf[2](5). If BLACKLISTNEWONLY=No, then they are applied regardless of the
           connection tracking state of the packet. If BLACKLISTNEWONLY=Yes, they are applied to
           connections in the NEW and INVALID states.

           When there are rules in this sectionas well as in shorewall-blrules (5), those in this
           section are processed last.

       ALL
           This section was added in Shorewall 4.4.23. Rules in this section are applied,
           regardless of the connection tracking state of the packet.

       ESTABLISHED
           Packets in the ESTABLISHED state are processed by rules in this section.

           The only ACTIONs allowed in this section are ACCEPT, DROP, REJECT, LOG and QUEUE

           There is an implicit ACCEPT rule inserted at the end of this section.

       RELATED
           Packets in the RELATED state are processed by rules in this section.

           The only ACTIONs allowed in this section are ACCEPT, DROP, REJECT, LOG and QUEUE

           There is an implicit ACCEPT rule inserted at the end of this section.

       NEW
           Packets in the NEW, INVALID and UNTRACKED states are processed by rules in this
           section.

           Note
           If you are not familiar with Netfilter to the point where you are comfortable with the
           differences between the various connection tracking states, then it is suggested that
           you omit the ESTABLISHED and RELATED sections and place all of your non-blacklisting
           rules in the NEW section (That's after the line that reads SECTION NEW').

           Warning
           If you specify FASTACCEPT=Yes in shorewall.conf[2](5) then the BLACKLIST, ALL,
           ESTABLISHED and RELATED sections must be empty.

       You may omit any section that you don't need. If no Section Headers appear in the file
       then all rules are assumed to be in the NEW section.

       When defining rules that rewrite the destination IP address and/or port number (namely
       DNAT and REDIRECT rules), it is important to keep straight which columns in the file
       specify the packet before rewriting and which specify how the packet will look after
       rewriting.

       ·   The DEST column specifies the final destination for the packet after rewriting and can
           include the final IP address and/or port number.

       ·   The remaining columns specify characteristics of the packet before rewriting. In
           particular, the ORIGINAL DEST column gives the original destination IP address of the
           packet and the DEST PORT(S) column give the original destination port(s).

       The columns in the file are as follows (where the column name is followed by a different
       name in parentheses, the different name is used in the alternate specification syntax).

       ACTION - target[:{log-level|none}[!][:tag]]
           Specifies the action to be taken if the connection request matches the rule.  target
           must be one of the following.

           ACCEPT
               Allow the connection request.

           ACCEPT+
               like ACCEPT but also excludes the connection from any subsequent matching DNAT[-]
               or REDIRECT[-] rules. Not available in the BLACKLIST section.

           ACCEPT!
               like ACCEPT but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5). Not available in the BLACKLIST section.

           A_ACCEPT, A_ACCEPT+ and A_ACCEPT!
               Added in Shorewall 4.4.20. Audited versions of ACCEPT, ACCEPT+ and ACCEPT!
               respectively. Require AUDIT_TARGET support in the kernel and iptables. A_ACCEPT+
               and A_ACCEPT! are not available in the BLACKLIST section.

           NONAT
               Excludes the connection from any subsequent DNAT[-] or REDIRECT[-] rules but
               doesn't generate a rule to accept the traffic. Not available in the BLACKLIST
               section.

           DROP
               Ignore the request.

           DROP!
               like DROP but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5). Not available in the BLACKLIST section. Not available in the
               BLACKLIST section.

           A_DROP and A_DROP!
               Added in Shorewall 4.4.20. Audited versions of DROP and DROP! respectively.
               Require AUDIT_TARGET support in the kernel and iptables. A_DROP! is not available
               in the BLACKLIST section. A_DROP! is not available in the BLACKLIST section.

           REJECT
               disallow the request and return an icmp-unreachable or an RST packet.

           REJECT!
               like REJECT but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5). Not available in the BLACKLIST section.

           A_REJECT AND A_REJECT!
               Added in Shorewall 4.4.20. Audited versions of REJECT and REJECT! respectively.
               Require AUDIT_TARGET support in the kernel and iptables. A_REJECT! is not
               available in the BLACKLIST section.

           DNAT
               Forward the request to another system (and optionally another port).

           DNAT-
               Advanced users only.

               Like DNAT but only generates the DNAT iptables rule and not the companion ACCEPT
               rule. Not available in the BLACKLIST section.

           REDIRECT
               Redirect the request to a server running on the firewall.

           REDIRECT-
               Advanced users only.

               Like REDIRECT but only generates the REDIRECT iptables rule and not the companion
               ACCEPT rule. Not available in the BLACKLIST section.

           CONTINUE
               For experts only.

               Do not process any of the following rules for this (source zone,destination zone).
               If the source and/or destination IP address falls into a zone defined later in
               shorewall-zones[3](5) or in a parent zone of the source or destination zones, then
               this connection request will be passed to the rules defined for that (those)
               zone(s). See shorewall-nesting[4](5) for additional information.

           CONTINUE!
               like CONTINUE but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5). Not available in the BLACKLIST section.

           LOG
               Simply log the packet and continue with the next rule.

           QUEUE
               Queue the packet to a user-space application such as ftwall
               (http://p2pwall.sf.net). The application may reinsert the packet for further
               processing.

           QUEUE!
               like QUEUE but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5). Not available in the BLACKLIST section.

           NFLOG[(nflog-parameters)]
               queues matching packets to a backend logging daemon via a netlink socket then
               continues to the next rule. See
               http://www.shorewall.net/shorewall_logging.html[5].

           NFQUEUE[(queuenumber)]
               Queues the packet to a user-space application using the nfnetlink_queue mechanism.
               If a queuenumber is not specified, queue zero (0) is assumed.

           NFQUEUE![(queuenumber)]
               like NFQUEUE but exempts the rule from being suppressed by OPTIMIZE=1 in
               shorewall.conf[2](5).

           COUNT
               Simply increment the rule's packet and byte count and pass the packet to the next
               rule.

           COMMENT
               the rest of the line will be attached as a comment to the Netfilter rule(s)
               generated by the following entries. The comment will appear delimited by "/* ...
               */" in the output of "shorewall show <chain>". To stop the comment from being
               attached to further rules, simply include COMMENT on a line by itself.

           action
               The name of an action declared in shorewall-actions[6](5) or in
               /usr/share/shorewall/actions.std.

           macro[(macrotarget)]
               The name of a macro defined in a file named macro.macro. If the macro accepts an
               action parameter (Look at the macro source to see if it has PARAM in the TARGET
               column) then the macro name is followed by the parenthesized macrotarget (ACCEPT,
               DROP, REJECT, ...) to be substituted for the parameter.

               Example: FTP(ACCEPT).

               The older syntax where the macro name and the target are separated by a slash
               (e.g. FTP/ACCEPT) is still allowed but is deprecated.

           ADD(ipset:flags)
               Added in Shorewall 4.4.12. Causes addresses and/or port numbers to be added to the
               named ipset. The flags specify the address or tupple to be added to the set and
               must match the type of ipset involved. For example, for an iphash ipset, either
               the SOURCE or DESTINATION address can be added using flags src or dst respectively
               (see the -A command in ipset (8)).

               ADD is non-terminating. Even if a packet matches the rule, it is passed on to the
               next rule.

           DEL(ipset:flags)
               Added in Shorewall 4.4.12. Causes an entry to be deleted from the named ipset. The
               flags specify the address or tupple to be deleted from the set and must match the
               type of ipset involved. For example, for an iphash ipset, either the SOURCE or
               DESTINATION address can be deletec using flags src or dst respectively (see the -D
               command in ipset (8)).

               DEL is non-terminating. Even if a packet matches the rule, it is passed on to the
               next rule.

           WHITELIST
               Added in Shorewall 4.4.25. May only appear in the BLACKLIST section and exempts
               the packet from following rules in that section.

           The target may optionally be followed by ":" and a syslog log level (e.g, REJECT:info
           or Web(ACCEPT):debug). This causes the packet to be logged at the specified level.
           Note that if the ACTION involves destination network address translation (DNAT,
           REDIRECT, etc.) then the packet is logged before the destination address is rewritten.

           If the ACTION names an action declared in shorewall-actions[6](5) or in
           /usr/share/shorewall/actions.std then:

           ·   If the log level is followed by "!' then all rules in the action are logged at the
               log level.

           ·   If the log level is not followed by "!" then only those rules in the action that
               do not specify logging are logged at the specified level.

           ·   The special log level none!  suppresses logging by the action.

           You may also specify ULOG or NFLOG (must be in upper case) as a log level.This will
           log to the ULOG or NFLOG target for routing to a separate log through use of ulogd
           (http://www.netfilter.org/projects/ulogd/index.html).

           Actions specifying logging may be followed by a log tag (a string of alphanumeric
           characters) which is appended to the string generated by the LOGPREFIX (in
           shorewall.conf[2](5)).

           Example: ACCEPT:info:ftp would include 'ftp ' at the end of the log prefix generated
           by the LOGPREFIX setting.

       SOURCE -
       {zone|zone-list[+]|{all|any}[+][-]}[:interface][:{address-or-range[,address-or-range]...[exclusion]|exclusion|+ipset}
           Source hosts to which the rule applies. May be a zone declared in
           /etc/shorewall/zones, $FW to indicate the firewall itself, all, all+, all-, all+- or
           none.

           Beginning with Shorewall 4.4.13, you may use a zone-list which consists of a
           comma-separated list of zones declared in shorewall-zones[3] (5). Ths zone-list may be
           optionally followed by "+" to indicate that the rule is to apply to intra-zone traffic
           as well as inter-zone traffic.

           When none is used either in the SOURCE or DEST column, the rule is ignored.

           all means "All Zones", including the firewall itself.  all- means "All Zones, except
           the firewall itself". When all[-] is used either in the SOURCE or DEST column
           intra-zone traffic is not affected. When all+[-] is "used, intra-zone traffic is
           affected. Beginning with Shorewall 4.4.13, exclusion is supported -- see see
           shorewall-exclusion[7](5).

           Except when all[+][-] or any[+][-] is specified, clients may be further restricted to
           a list of networks and/or hosts by appending ":" and a comma-separated list of network
           and/or host addresses. Hosts may be specified by IP or MAC address; mac addresses must
           begin with "~" and must use "-" as a separator.

           The above restriction on all[+][-] and any[+][-] is removed in Shorewall-4.4.13.

           any is equivalent to all when there are no nested zones. When there are nested zones,
           any only refers to top-level zones (those with no parent zones). Note that any
           excludes all vserver zones, since those zones are nested within the firewall zone.

           Hosts may also be specified as an IP address range using the syntax
           lowaddress-highaddress. This requires that your kernel and iptables contain iprange
           match support. If your kernel and iptables have ipset match support then you may give
           the name of an ipset prefaced by "+". The ipset name may be optionally followed by a
           number from 1 to 6 enclosed in square brackets ([]) to indicate the number of levels
           of source bindings to be matched.

           Beginning with Shorewall 4.4.17, the primary IP address of a firewall interface can be
           specified by an apersand ('&') followed by the logican name of the interface as found
           in the INTERFACE column of shorewall-interfaces[8] (5).

           You may exclude certain hosts from the set already defined through use of an exclusion
           (see shorewall-exclusion[7](5)).

           Examples:

           dmz:192.168.2.2
               Host 192.168.2.2 in the DMZ

           net:155.186.235.0/24
               Subnet 155.186.235.0/24 on the Internet

           loc:192.168.1.1,192.168.1.2
               Hosts 192.168.1.1 and 192.168.1.2 in the local zone.

           loc:~00-A0-C9-15-39-78
               Host in the local zone with MAC address 00:A0:C9:15:39:78.

           net:192.0.2.11-192.0.2.17
               Hosts 192.0.2.11-192.0.2.17 in the net zone.

           net:!192.0.2.11-192.0.2.17
               All hosts in the net zone except for 192.0.2.11-192.0.2.17.

           net:155.186.235.0/24!155.186.235.16/28
               Subnet 155.186.235.0/24 on the Internet except for 155.186.235.16/28

           $FW:&eth0
               The primary IP address of eth0 in the firewall zone (Shorewall 4.4.17 and later).

       DEST -
       {zone|zone-list[+]|{all|any}[+][-]}[:{interface|address-or-range[,address-or-range]...[exclusion]|exclusion|+ipset}][:port[:random]]
           Location of Server. May be a zone declared in shorewall-zones[3](5), $FW to indicate
           the firewall itself, all.  all+ or none.

           Beginning with Shorewall 4.4.13, you may use a zone-list which consists of a
           comma-separated list of zones declared in shorewall-zones[3] (5). Ths zone-list may be
           optionally followed by "+" to indicate that the rule is to apply to intra-zone traffic
           as well as inter-zone traffic.

           When none is used either in the SOURCE or DEST column, the rule is ignored.

           When all is used either in the SOURCE or DEST column intra-zone traffic is not
           affected. When all+ is used, intra-zone traffic is affected. Beginning with Shorewall
           4.4.13, exclusion is supported -- see see shorewall-exclusion[7](5).

           any is equivalent to all when there are no nested zones. When there are nested zones,
           any only refers to top-level zones (those with no parent zones).

           The zone should be omitted in DNAT-, REDIRECT- and NONAT rules.

           If the DEST zone is a bport zone, then either:

            1. the SOURCE must be all[+][-], or

            2. the SOURCE zone must be another bport zone associated with the same bridge, or

            3. the SOURCE zone must be an ipv4 zone that is associated with only the same bridge.

           Except when all[+]|[-] is specified, the server may be further restricted to a
           particular network, host or interface by appending ":" and the network, host or
           interface. See SOURCE above.

           You may exclude certain hosts from the set already defined through use of an exclusion
           (see shorewall-exclusion[7](5)).

           Restrictions:

           1. MAC addresses are not allowed (this is a Netfilter restriction).

           2. You may not specify both an interface and an address.

           Like in the SOURCE column, you may specify a range of IP addresses using the syntax
           lowaddress-highaddress. When the ACTION is DNAT or DNAT-, the connections will be
           assigned to addresses in the range in a round-robin fashion.

           If you kernel and iptables have ipset match support then you may give the name of an
           ipset prefaced by "+". The ipset name may be optionally followed by a number from 1 to
           6 enclosed in square brackets ([]) to indicate the number of levels of destination
           bindings to be matched. Only one of the SOURCE and DEST columns may specify an ipset
           name.

           Beginning with Shorewall 4.4.17, the primary IP address of a firewall interface can be
           specified by an apersand ('&') followed by the logical name of the interface as found
           in the INTERFACE column of shorewall-interfaces[8] (5).

           The port that the server is listening on may be included and separated from the
           server's IP address by ":". If omitted, the firewall will not modifiy the destination
           port. A destination port may only be included if the ACTION is DNAT or REDIRECT.

           Example:
               loc:192.168.1.3:3128 specifies a local server at IP address 192.168.1.3 and
               listening on port 3128.

           The port may be specified as a service name. You may specify a port range in the form
           lowport-highport to cause connections to be assigned to ports in the range in
           round-robin fashion. When a port range is specified, lowport and highport must be
           given as integers; service names are not permitted. Additionally, the port range may
           be optionally followed by :random which causes assignment to ports in the list to be
           random.

           If the ACTION is REDIRECT or REDIRECT-, this column needs only to contain the port
           number on the firewall that the request should be redirected to. That is equivalent to
           specifying $FW::port.

       PROTO- {-|tcp:syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all}
           Optional Protocol - ipp2p* requires ipp2p match support in your kernel and iptables.
           tcp:syn implies tcp plus the SYN flag must be set and the RST,ACK and FIN flags must
           be reset.

           Beginning with Shorewall 4.4.19, this column can contain a comma-separated list of
           protocol-numbers and/or protocol names.

       DEST PORT(S) (dport) - {-|port-name-number-or-range[,port-name-number-or-range]...}
           Optional destination Ports. A comma-separated list of Port names (from services(5)),
           port numbers or port ranges; if the protocol is icmp, this column is interpreted as
           the destination icmp-type(s). ICMP types may be specified as a numeric type, a
           numberic type and code separated by a slash (e.g., 3/4), or a typename. See
           http://www.shorewall.net/configuration_file_basics.htm#ICMP. Note that prior to
           Shorewall 4.4.19, only a single ICMP type may be listsed.

           If the protocol is ipp2p, this column is interpreted as an ipp2p option without the
           leading "--" (example bit for bit-torrent). If no port is given, ipp2p is assumed.

           A port range is expressed as lowport:highport.

           This column is ignored if PROTO = all but must be entered if any of the following
           columns are supplied. In that case, it is suggested that this field contain a dash
           (-).

           If your kernel contains multi-port match support, then only a single Netfilter rule
           will be generated if in this list and the CLIENT PORT(S) list below:

           1. There are 15 or less ports listed.

           2. No port ranges are included or your kernel and iptables contain extended multiport
           match support.

       SOURCE PORT(S) (sport) - {-|port-name-number-or-range[,port-name-number-or-range]...}
           Optional port(s) used by the client. If omitted, any source port is acceptable.
           Specified as a comma- separated list of port names, port numbers or port ranges.

               Warning
               Unless you really understand IP, you should leave this column empty or place a
               dash (-) in the column. Most people who try to use this column get it wrong.
           If you don't want to restrict client ports but need to specify an ORIGINAL DEST in the
           next column, then place "-" in this column.

           If your kernel contains multi-port match support, then only a single Netfilter rule
           will be generated if in this list and the DEST PORT(S) list above:

           1. There are 15 or less ports listed.

           2. No port ranges are included or your kernel and iptables contain extended multiport
           match support.

       ORIGINAL DEST (origdest) - [-|address[,address]...[exclusion]|exclusion]
           Optional. If ACTION is DNAT[-] or REDIRECT[-] then if this column is included and is
           different from the IP address given in the DEST column, then connections destined for
           that address will be forwarded to the IP and port specified in the DEST column.

           A comma-separated list of addresses may also be used. This is most useful with the
           REDIRECT target where you want to redirect traffic destined for particular set of
           hosts. Finally, if the list of addresses begins with "!" (exclusion) then the rule
           will be followed only if the original destination address in the connection request
           does not match any of the addresses listed.

           Beginning with Shorewall 4.4.17, the primary IP address of a firewall interface can be
           specified by an apersand ('&') followed by the logical name of the interface as found
           in the INTERFACE column of shorewall-interfaces[8] (5).

           For other actions, this column may be included and may contain one or more addresses
           (host or network) separated by commas. Address ranges are not allowed. When this
           column is supplied, rules are generated that require that the original destination
           address matches one of the listed addresses. This feature is most useful when you want
           to generate a filter rule that corresponds to a DNAT- or REDIRECT- rule. In this
           usage, the list of addresses should not begin with "!".

           It is also possible to specify a set of addresses then exclude part of those
           addresses. For example, 192.168.1.0/24!192.168.1.16/28 specifies the addresses
           192.168.1.0-182.168.1.15 and 192.168.1.32-192.168.1.255. See
           shorewall-exclusion[7](5).

           See http://shorewall.net/PortKnocking.html[9] for an example of using an entry in this
           column with a user-defined action rule.

       RATE LIMIT (rate) - [-|[{s|d}:[[name]:]]]rate/{sec|min|hour|day}[:burst]
           You may optionally rate-limit the rule by placing a value in this column:

           rate is the number of connections per interval (sec or min) and burst is the largest
           burst permitted. If no burst is given, a value of 5 is assumed. There may be no no
           whitespace embedded in the specification.

           Example: 10/sec:20

           When s: or d: is specified, the rate applies per source IP address or per destination
           IP address respectively. The name may be chosen by the user and specifies a hash table
           to be used to count matching connections. If not given, the name shorewallN (where N
           is a unique integer) is assumed. Where more than one rule specifies the same name, the
           connections counts for the rules are aggregated and the individual rates apply to the
           aggregated count.

           Example: s:ssh:3/min:5

       USER/GROUP (user) - [!][user-name-or-number][:group-name-or-number][+program-name]
           This optional column may only be non-empty if the SOURCE is the firewall itself.

           When this column is non-empty, the rule applies only if the program generating the
           output is running under the effective user and/or group specified (or is NOT running
           under that id if "!" is given).

           Examples:

           joe
               program must be run by joe

           :kids
               program must be run by a member of the 'kids' group

           !:kids
               program must not be run by a member of the 'kids' group

           +upnpd
               program named upnpd

                   Important
                   The ability to specify a program name was removed from Netfilter in kernel
                   version 2.6.14.

       MARK - [!]value[/mask][:C]
           Defines a test on the existing packet or connection mark. The rule will match only if
           the test returns true.

           If you don't want to define a test but need to specify anything in the following
           columns, place a "-" in this field.

           !
               Inverts the test (not equal)

           value
               Value of the packet or connection mark.

           mask
               A mask to be applied to the mark before testing.

           :C
               Designates a connection mark. If omitted, the packet mark's value is tested.

       CONNLIMIT - [!]limit[:mask]
           May be used to limit the number of simultaneous connections from each individual host
           to limit connections. Requires connlimit match in your kernel and iptables. While the
           limit is only checked on rules specifying CONNLIMIT, the number of current connections
           is calculated over all current connections from the SOURCE host. By default, the limit
           is applied to each host but can be made to apply to networks of hosts by specifying a
           mask. The mask specifies the width of a VLSM mask to be applied to the source address;
           the number of current connections is then taken over all hosts in the subnet
           source-address/mask. When !  is specified, the rule matches when the number of
           connection exceeds the limit.

       TIME - timeelement[&timelement...]
           May be used to limit the rule to a particular time period each day, to particular days
           of the week or month, or to a range defined by dates and times. Requires time match
           support in your kernel and iptables.

           timeelement may be:

           timestart=hh:mm[:ss]
               Defines the starting time of day.

           timestop=hh:mm[:ss]
               Defines the ending time of day.

           utc
               Times are expressed in Greenwich Mean Time.

           localtz
               Times are expressed in Local Civil Time (default).

           weekdays=ddd[,ddd]...
               where ddd is one of Mon, Tue, Wed, Thu, Fri, Sat or Sun

           monthdays=dd[,dd],...
               where dd is an ordinal day of the month

           datestart=yyyy[-mm[-dd[Thh[:mm[:ss]]]]]
               Defines the starting date and time.

           datestop=yyyy[-mm[-dd[Thh[:mm[:ss]]]]]
               Defines the ending date and time.

       HEADERS
           Added in Shorewall 4.4.15. Not used in IPv4 configurations. If you with to supply a
           value for one of the later columns, enter '-' in this column.

       SWITCH - [!]switch-name
           Added in Shorewall 4.4.24 and allows enabling and disabling the rule without requiring
           shorewall restart.

           The rule is enabled if the value stored in /proc/net/nf_condition/switch-name is 1.
           The rule is disabled if that file contains 0 (the default). If '!' is supplied, the
           test is inverted such that the rule is enabled if the file contains 0.  switch-name
           must begin with a letter and be composed of letters, decimal digits, underscores or
           hyphens. Switch names must be 30 characters or less in length.

           Switches are normally off. To turn a switch on:
               echo 1 >
                           /proc/net/nf_condition/switch-name
           To turn it off again:
               echo 0 >
                           /proc/net/nf_condition/switch-name
           Switch settings are retained over shorewall restart.

EXAMPLES

       Example 1:
           Accept SMTP requests from the DMZ to the internet

                        #ACTION SOURCE  DEST PROTO      DEST    SOURCE  ORIGINAL
                        #                               PORT    PORT(S) DEST
                        ACCEPT  dmz     net       tcp   smtp

       Example 2:
           Forward all ssh and http connection requests from the internet to local system
           192.168.1.3

                       #ACTION SOURCE  DEST            PROTO   DEST    SOURCE  ORIGINAL
                       #                                       PORT    PORT(S) DEST
                       DNAT    net     loc:192.168.1.3 tcp     ssh,http

       Example 3:
           Forward all http connection requests from the internet to local system 192.168.1.3
           with a limit of 3 per second and a maximum burst of 10

                       #ACTION SOURCE DEST            PROTO  DEST  SOURCE  ORIGINAL RATE
                       #                                     PORT  PORT(S) DEST     LIMIT
                       DNAT    net    loc:192.168.1.3 tcp    http  -       -        3/sec:10

       Example 4:
           Redirect all locally-originating www connection requests to port 3128 on the firewall
           (Squid running on the firewall system) except when the destination address is
           192.168.2.2

                       #ACTION  SOURCE DEST      PROTO DEST    SOURCE  ORIGINAL
                       #                               PORT    PORT(S) DEST
                       REDIRECT loc    3128      tcp   www      -      !192.168.2.2

       Example 5:
           All http requests from the internet to address 130.252.100.69 are to be forwarded to
           192.168.1.3

                       #ACTION  SOURCE DEST            PROTO   DEST    SOURCE  ORIGINAL
                       #                                       PORT    PORT(S) DEST
                       DNAT      net   loc:192.168.1.3 tcp     80      -       130.252.100.69

       Example 6:
           You want to accept SSH connections to your firewall only from internet IP addresses
           130.252.100.69 and 130.252.100.70

                       #ACTION  SOURCE DEST            PROTO   DEST    SOURCE  ORIGINAL
                       #                                       PORT    PORT(S) DEST
                       ACCEPT   net:130.252.100.69,130.252.100.70 $FW \
                                                       tcp     22

       Example 7:
           You wish to accept connections from the internet to your firewall on port 2222 and you
           want to forward them to local system 192.168.1.3, port 22

                       #ACTION  SOURCE DEST                PROTO   DEST    SOURCE  ORIGINAL
                       #                                           PORT    PORT(S) DEST
                       DNAT     net    loc:192.168.1.3:22  tcp     2222

       Example 8:
           You want to redirect connection requests to port 80 randomly to the port range 81-90.

                       #ACTION  SOURCE DEST                PROTO DEST    SOURCE  ORIGINAL
                       #                                         PORT    PORT(S) DEST
                       REDIRECT net    $FW::81-90:random   tcp   www

       Example 9:
           Shorewall does not impose as much structure on the Netfilter rules in the 'nat' table
           as it does on those in the filter table. As a consequence, when using Shorewall
           versions before 4.1.4, care must be exercised when using DNAT and REDIRECT rules with
           zones defined with wildcard interfaces (those ending with '+'. Here is an example:

           shorewall-zones[3](8):

                       #ZONE       TYPE    OPTIONS
                       fw          firewall
                       net         ipv4
                       dmz         ipv4
                       loc         ipv4

           shorewall-interfaces[8](8):

                       #ZONE       INTERFACE       BROADCAST      OPTIONS
                       net         ppp0
                       loc         eth1            detect
                       dmz         eth2            detect
                       -           ppp+                           # Addresses are assigned from 192.168.3.0/24

           shorewall-host[10](8):

                       #ZONE       HOST(S)              OPTIONS
                       loc         ppp+:192.168.3.0/24

           rules:

                       #ACTION     SOURCE          DEST       PROTO       DEST
                       #                                                  PORT(S)
                       REDIRECT    loc             3128       tcp         80

           Note that it would have been tempting to simply define the loc zone entirely in
           shorewall-interfaces(8):

                       #******************* INCORRECT *****************
                       #ZONE       INTERFACE       BROADCAST      OPTIONS
                       net         ppp0
                       loc         eth1            detect
                       loc         ppp+
                       dmz         eth2

           This would have made it impossible to run a internet-accessible web server in the DMZ
           because all traffic entering ppp+ interfaces would have been redirected to port 3128
           on the firewall and there would have been no net->fw ACCEPT rule for that traffic.

       Example 10:
           Add the tupple (source IP, dest port, dest IP) of an incoming SSH connection to the
           ipset S:

                       #ACTION                       SOURCE           DEST           PROTO       DEST
                       #                                                             PORT(S)
                       ADD(+S:dst,src,dst)           net              fw             tcp         22

       Example 11:
           You wish to limit SSH connections from remote systems to 1/min with a burst of three
           (to allow for limited retry):

                       #ACTION     SOURCE          DEST       PROTO       DEST         SOURCE    ORIGINAL         RATE
                       #                                                  PORT(S)      PORT(S)   DEST             LIMIT
                       SSH(ACCEPT) net             all        -           -            -         -                s:1/min:3

       Example 12:
           Forward port 80 to dmz host $BACKUP if switch 'primary_down' is on.

                       #ACTION     SOURCE          DEST        PROTO       DEST         SOURCE    ORIGINAL   RATE      USER/     MARK    CONNLIMIT     TIME     HEADERS    SWITCH
                       #                                                   PORT(S)      PORT(S)   DEST       LIMIT     GROUP
                       DNAT        net             dmz:$BACKUP tcp         80           -         -          -         -         -       -             -        -          primary_down

FILES

       /etc/shorewall/rules

SEE ALSO

       http://www.shorewall.net/ipsets.html

       http://shorewall.net/configuration_file_basics.htm#Pairs

       shorewall(8), shorewall-accounting(5), shorewall-actions(5), shorewall-blacklist(5),
       shorewall-hosts(5), shorewall_interfaces(5), shorewall-ipsets(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.conf(5),
       shorewall-secmarks(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
       shorewall-tcrules(5), shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)

NOTES

        1. shorewall-policy
           http://www.shorewall.net/manpages/shorewall-policy.html

        2. shorewall.conf
           http://www.shorewall.net/manpages/shorewall.conf.html

        3. shorewall-zones
           http://www.shorewall.net/manpages/shorewall-zones.html

        4. shorewall-nesting
           http://www.shorewall.net/manpages/shorewall-nesting.html

        5. http://www.shorewall.net/shorewall_logging.html
           http://www.shorewall.net/shorewall.logging.html

        6. shorewall-actions
           http://www.shorewall.net/manpages/shorewall-actions.html

        7. shorewall-exclusion
           http://www.shorewall.net/manpages/shorewall-exclusion.html

        8. shorewall-interfaces
           http://www.shorewall.net/manpages/shorewall-interfaces.html

        9. http://shorewall.net/PortKnocking.html
           http://www.shorewall.net/manpages/../PortKnocking.html

       10. shorewall-host
           http://www.shorewall.net/manpages/shorewall-hosts.html

[FIXME: source]                             12/13/2011                         SHOREWALL-RULES(5)