User`s guide

Dual Network Options
Chapter 17 Command Line Interface 278
Dual Network Options
Source Based Routing
When more than one router is needed, with each network interface using a
different router, set up source-based routing on the Passport.
The following commands are needed to be run for source based routing on
the Passport
# /sbin/ip rule add from $IP table $TBL
# /sbin/ip route add default dev $ETH via $GW table $TBL
# /sbin/ip route add $NET dev $ETH table $TBL
where:
$IP is an IP address which should use a non-default gateway.
$NET is an IP network which should be routed straight, that is, not through
the gateway.
$ETH is the network interface to route to
$GW is a gateway for this IP address.
$TBL is any free table name which is defined in /etc/iproute2/rt_tables file.
Note that every new non-standard gateway will require another table
number.
If the Source based routing option is enabled under Network -> IP
configuration in the Passport, then /etc/iproute2/setsbr.sh script will be
started to run commands above for the interface eth1 automatically.
That is, $IP will be the IP address of eth1 interface, $NET will be the subnet
mask of eth1 interface, $ETH will be eth0, $GW will be the gateway of eth1
interface and $TBL will be auxtbl by default.
This script can be modified to make eth1 as the main default gateway or
add some more conditions.
For more information about source based routing from 'ip rule' and 'ip route'
section of the Linux ip man page or Appendix D of "Guide to IP Layer
Network Administration with Linux" (http://linux-ip.net/html/linux-
ip.html#tools-ip-routing)