providers — Shorewall6 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 firewall.

  • 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 - value

A FWMARK value used in your shorewall6-tcrules(5) file to direct packets to this provider.

If HIGH_ROUTE_MARKS=Yes in shorewall6.conf(5), 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.

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.

INTERFACE - interface

The name of the network interface to the provider. Must be listed in shorewall6-interfaces(5).

GATEWAY - {-|address|detect}

The IP address of the provider's gateway router.

You can enter "detect" here and Shorewall6 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 whitespace.


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

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


Shorewall6 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 interface.


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 shorewall6-interfaces(5) is assumed.


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, Shorewall6 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.

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 2002:ce7c:92b4:1::2. Your DMZ interface is eth2

        Squid   1       1    -          eth2      2002:ce7c:92b4:1::2  -
Example 2:

eth0 connects to ISP 1. The ISP's gateway router has IP address 2001:ce7c:92b4:1::2.

eth1 connects to ISP 2. The ISP's gateway router has IP address 2001:d64c:83c9:12::8b.

eth2 connects to a local network.

        ISP1  1       1    main      eth0     2001:ce7c:92b4:1::2   track      eth2
        ISP2  2       2    main      eth1     2001:d64c:83c9:12::8b track      eth2




shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5), shorewall6-maclist(5), shorewall6-params(5), shorewall6-policy(5), shorewall6-route_rules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)