How to assign 2 IP adresses ?

Hello
I use the Lacie at Home, with 2 internet providers, so 2 network.
I would like to assign to 2 IP adresses to my NAS.
With a standard linux, I will add a eth0.0
But how to do with the fvdwsl firmware ?
Thanks.
ps:
for now, I've added a line in /etc/init.d/rc.banner :
exec("/sbin/ifconfig eth0:0 192.168.0.133 netmask 255.255.255.0 up", $out, $ret)
is it the best way to do ?
I use the Lacie at Home, with 2 internet providers, so 2 network.
I would like to assign to 2 IP adresses to my NAS.
With a standard linux, I will add a eth0.0
But how to do with the fvdwsl firmware ?
Thanks.
ps:
for now, I've added a line in /etc/init.d/rc.banner :
exec("/sbin/ifconfig eth0:0 192.168.0.133 netmask 255.255.255.0 up", $out, $ret)
is it the best way to do ?