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       providers - Shorewall Providers file




       This file is used to define additional routing tables. You will want to
       define an additional table if:

       ·   You have connections to more than one ISP or multiple connections
           to the same ISP

       ·   You run Squid as a transparent proxy on a host other than the

       ·   You have other requirements for policy routing.

       Each entry in the file defines a single routing table.

       If you wish to omit a column entry but want to include an entry in the
       next column, use "-" for the omitted entry.

       The columns in the file are as follows.

       NAME - name
           The provider name. Must be a valid shell variable name. The names
           'local', 'main', 'default' and 'unspec' are reserved and may not be
           used as provider names.

       NUMBER - number
           The provider number -- a number between 1 and 15. Each provider
           must be assigned a unique value.

       MARK (Optional) - value
           A FWMARK value used in your shorewall-tcrules(5)[1] file to direct
           packets to this provider.

           If HIGH_ROUTE_MARKS=Yes in shorewall.conf(5)[2], then the value
           must be a multiple of 256 between 256 and 65280 or their
           hexadecimal equivalents (0x0100 and 0xff00 with the low-order byte
           of the value being zero). Otherwise, the value must be between 1
           and 255. Each provider must be assigned a unique mark value. This
           column may be omitted if you don't use packet marking to direct
           connections to a particular provider and you don't specify track in
           the OPTIONS column.

       DUPLICATE - routing-table-name
           The name of an existing table to duplicate to create this routing
           table. May be main or the name of a previously listed provider. You
           may select only certain entries from the table to copy by using the
           COPY column below. This column should contain a dash ("-') when
           USE_DEFAULT_RT=Yes in shorewall.conf(5)[2].

       INTERFACE - interface[:address]
           The name of the network interface to the provider. Must be listed
           in shorewall-interfaces(5)[3]. In general, that interface should
           not have the proxyarp option specified unless loose is given in the
           OPTIONS column of this entry.

           Where more than one provider is serviced through a single
           interface, the interface must be followed by a colon and the IP
           address of the interface that is supplied by the associated

       GATEWAY - {-|address|detect}
           The IP address of the provider's gateway router.

           You can enter "detect" here and Shorewall will attempt to detect
           the gateway automatically.

           For PPP devices, you may omit this column.

       OPTIONS (Optional) - [-|option[,option]...]
           A comma-separated list selected from the following. The order of
           the options is not significant but the list may contain no embedded

               If specified, inbound connections on this interface are to be
               tracked so that responses may be routed back out this same

               You want to specify track if internet hosts will be connecting
               to local servers through this provider.

               Beginning with Shorewall 4.4.3, track defaults to the setting
               of the TRACK_PROVIDERS option in shorewall.conf[4] (5). If you
               set TRACK_PROVIDERS=Yes and want to override that setting for
               an individual provider, then specify notrack (see below).

               The providers that have balance specified will get outbound
               traffic load-balanced among them. By default, all interfaces
               with balance specified will have the same weight (1). You can
               change the weight of an interface by specifying balance=weight
               where weight is the weight of the route out of this interface.

               Shorewall normally adds a routing rule for each IP address on
               an interface which forces traffic whose source is that IP
               address to be sent using the routing table for that interface.
               Setting loose prevents creation of such rules on this

               Added in Shorewall 4.4.3. When specified, turns off track.

           optional (deprecated)
               If the interface named in the INTERFACE column is not up and
               configured with an IPv4 address then ignore this provider. If
               not specified, the value of the optional option for the
               INTERFACE in shorewall-interfaces(5)[3] is assumed. Use of that
               option is preferred to this one.

               Specifies the source address to use when routing to this
               provider and none is known (the local client has bound to the 0
               address). May not be specified when an address is given in the
               INTERFACE column. If this option is not used, Shorewall
               substitutes the primary IP address on the interface named in
               the INTERFACE column.

               Specifies the MTU when forwarding through this provider. If not
               given, the MTU of the interface named in the INTERFACE column
               is assumed.

               Indicates that a default route through the provider should be
               added to the default routing table (table 253). If a weight is
               given, a balanced route is added with the weight of this
               provider equal to the specified weight. If the option is given
               without a weight, an separate default route is added through
               the provider's gateway; the route has a metric equal to the
               provider's NUMBER. The option is ignored with a warning message
               if USE_DEFAULT_RT=Yes in shorewall.conf.

       COPY - [{none|interface[,interface]...}]
           A comma-separated list of other interfaces on your firewall.
           Wildcards specified using an asterisk ("*") are permitted (e.g.,
           tun* ). Usually used only when DUPLICATE is main. Only copy routes
           through INTERFACE and through interfaces listed here. If you only
           wish to copy routes through INTERFACE, enter none in this column.


       Example 1:
           You run squid in your DMZ on IP address Your DMZ
           interface is eth2

                       Squid   1       1    -          eth2  -

       Example 2:
           eth0 connects to ISP 1. The IP address of eth0 is
           and the ISP's gateway router has IP address

           eth1 connects to ISP 2. The IP address of eth1 is and
           the ISP's gateway router has IP address

           eth2 connects to a local network.

                       #NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY          OPTIONS            COPY
                       ISP1  1       1    main      eth0 track,balance      eth2
                       ISP2  2       2    main      eth1  track,balance      eth2




       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-proxyarp(5), shorewall-route_rules(5),
       shorewall-routestopped(5), shorewall-rules(5), shorewall.conf(5),
       shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
       shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)


        1. shorewall-tcrules(5)

        2. shorewall.conf(5)

        3. shorewall-interfaces(5)

        4. shorewall.conf

[FIXME: source]                   06/17/2010