Hm!  Never heard of RH6.3 before.  Probably the successor to RH9.

You need to take advantage of the RPDB.  In particular, you may find this
documentation helpful:

  http://linux-ip.net/html/adv-multi-internet.html
  http://linux-ip.net/html/adv-multi-internet.html#adv-multi-internet-outbound

For some background on route selection:

  http://linux-ip.net/html/routing-selection.html
  http://linux-ip.net/html/routing-selection.html#routing-selection-adv

Using Multiple Connections to the Internet for Inbound and Outbound Connections and for Outbound traffic Using Multiple Connections to the Internet and seems i need the second one, and this is almost not documented, or maybe i just didn't find examples.

Note, that routing and iptables must be synchronized in order for you to
attain the desired result.

If your default route in table main is through 213.34.9.x, then here's a
teaser (you'll need to tweak it a bit to get things right):

# echo 5 link213180 >> /etc/iproute2/rt_tables
# ip rule add from 192.168.30.2 table link213180
  ...
# ip rule add from 192.168.30.5 table link213180
# ip route show table main \
>   | while read ROUTE ; do
>     ip route add table link213180 $ROUTE
> done
# ip route change table link213180 default via 213.180.9.x