LARTC - Oct 2005 - Two differente networks at the same ethernet pci adapter

Hello all,

    I need to put an IP alias to the same ethernet card, like this:

eth0 - IP1/MASK1/BROADCAST1

eth0:1 - IP2/MASK2/BROADCAST2

    In this box I will have another card that conects to a LAN netowork. I 
need this two alias in eth0 becouse I have two routes do take, but it seens 
to do not work. This is the script I am using (this scripts works fine when 
I have two ethernet cards like eth0 and eth1 for backbone and eth2 for LAN):

---- SCRIPT BEGINING /usr/loca/firewall/loadbalance ----
#!/bin/sh
#-------------------------
# Configuracao de redirecionamento de portas para os links
# Balanceamento de carga entre pontos de rede
# ++++++++++++++++++++++++
# Script criado por NATANIEL KLUG
#-------------------------
#
#----
# Variaveis de sistema
#----
IPTABLES="/usr/local/sbin/iptables"
IP="/sbin/ip"
#
#----
# ENTRADA DE LINKS
#----
IF1=''eth0''
IF2=''eth0''
#
#----
# Declara as redes
#----
P1_NET=172.30.0.0/24''
P2_NET=''10.1.1.0/24''
#
#----
# Declara IPs
#----
IP1=''172.30.0.55''
IP2=''10.1.1.10''
#
#----
# Declara gateway das conexoes
#----
P1=''172.30.0.1''
P2=''10.1.1.1''
#
#----
# Mascara as redes e marca os pacotes
#----
$IPTABLES -t nat -A POSTROUTING -o $IF1 -j MASQUERADE
$IPTABLES -t nat -A POSTROUTING -o $IF2 -j MASQUERADE
#
#----
# Declaracao de rotas padrao para os links
#----
$IP route add $P1_NET dev $IF1 src $IP1 table T1
$IP route add default via $P1 table T1
$IP route add $P2_NET dev $IF2 src $IP2 table T2
$IP route add default via $P1 table T2
#
$IP route add $P1_NET dev $IF1 src $IP1
$IP route add $P2_NET dev $IF2 src $IP2
#
$IP route add default scope global nexthop via $P1 dev $IF1 weight 1 nexthop 
via $P2 dev $IF2 weight 1
#
$IP rule add from $IP1 table T1
$IP rule add from $IP2 table T2
#
#----
# Atualiza tabela de cache
#----
$IP route flush cache

---- END OS SCRIPT ---

What can I do (if there is something) for this to work?

Att,

Nataniel Klug