shorewall-providers

Description

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 (Optional) - value

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

If HIGH_ROUTE_MARKS=Yes in shorewall.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. 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).

INTERFACE - interface[:address]

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

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 provider.

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 whitespace.

track

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.

balance[=weight]

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 specifiying balance=weight where weight is the weight of the route out of this interface.

loose

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 interface.

optional

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) is assumed.

src=source-address

Added in Shorewall-perl 4.1.5. 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.

mtu=number

Added in Shorewall-perl 4.1.5. Specifies the MTU when forwarding through this provider. If not given, the MTU of the interface named in the INTERFACE column is assumed.

fallback[=weight]

Added in Shorewall-perl 4.2.5. 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.

Examples

Example 1:

You run squid in your DMZ on IP address 192.168.2.99. Your DMZ interface is eth2

        #NAME   NUMBER  MARK DUPLICATE  INTERFACE GATEWAY       OPTIONS
        Squid   1       1    -          eth2      192.168.2.99  -

Example 2:

eth0 connects to ISP 1. The IP address of eth0 is 206.124.146.176 and the ISP's gateway router has IP address 206.124.146.254.

eth1 connects to ISP 2. The IP address of eth1 is 130.252.99.27 and the ISP's gateway router has IP address 130.252.99.254.

eth2 connects to a local network.

        #NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY          OPTIONS            COPY
        ISP1  1       1    main      eth0      206.124.146.254 track,balance      eth2
        ISP2  2       2    main      eth1      130.252.99.254  track,balance      eth2

FILES

/etc/shorewall/providers

Name

Synopsis

Description

Examples

FILES

See ALSO