Ubuntu Manpages

rtrules

Shorewall Routing Rules file

/etc/shorewall/rtrules

Entries in this file cause traffic to be routed to one of the providers listed in shorewall-providers[1](5).

The columns in the file are as follows.

SOURCE (Optional) - {-|[&]interface|address|interface:address}

An ip address (network or host) that matches the source IP address in a packet. May also be specified as an interface name optionally followed by ":" and an address. If the device lo is specified, the packet must originate from the firewall itself.

Beginning with Shorewall 4.5.0, you may specify &interface in this column to indicate that the source is the primary IP address of the named interface.

DEST (Optional) - {-|address}

An ip address (network or host) that matches the destination IP address in a packet.

If you choose to omit either SOURCE or DEST, place "-" in that column. Note that you may not omit both SOURCE and DEST.

PROVIDER - {provider-name|provider-number|main}

The provider to route the traffic through. May be expressed either as the provider name or the provider number. May also be main or 254 for the main routing table. This can be used in combination with VPN tunnels, see example 2 below.

PRIORITY - priority

The rule's numeric priority which determines the order in which the rules are processed. Rules with equal priority are applied in the order in which they appear in the file.

1000-1999

Before Shorewall-generated 'MARK' rules

11000-11999

After 'MARK' rules but before Shorewall-generated rules for ISP interfaces.

26000-26999

After ISP interface rules but before 'default' rule.

MARK - {-|mark[/mask]}

Optional -- added in Shorewall 4.4.25. For this rule to be applied to a packet, the packet's mark value must match the mark when logically anded with the mask. If a mask is not supplied, Shorewall supplies a suitable provider mask.

Example 1:

You want all traffic coming in on eth1 to be routed to the ISP1 provider. 

        #SOURCE                 DEST            PROVIDER        PRIORITY      MASK
        eth1                    -               ISP1            1000

Example 2:

You use OpenVPN (routed setup /tunX) in combination with multiple providers. In this case you have to set up a rule to ensure that the OpenVPN traffic is routed back through the tunX interface(s) rather than through any of the providers. 10.8.0.0/24 is the subnet chosen in your OpenVPN configuration (server 10.8.0.0 255.255.255.0). 

         #SOURCE                 DEST            PROVIDER        PRIORITY     MASK
         -                       10.8.0.0/24     main            1000

/etc/shorewall/rtrules

http://shorewall.net/MultiISP.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-routestopped(5), shorewall-rules(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)

1.
shorewall-providers
http://www.shorewall.netshorewall-providers.html