Hello,
I'm trying to set up a little server that can share an internet
connection with two clients WITHOUT any router/hub/switch.
This is my network:


[client_1]:eth0(192.168.7.2) ========\
eth0:(192.168.7.1)[//////]
[//////]
[client_2]:eth0(192.168.7.3) ====== eth1:(192.168.7.10)[server]
[//////]
eth2:(192.168.7.100)[//////]
[adsl_mdm]:=========================/


Problem:

If I try to ping (from server) client_1, that's ok.
If I try to ping (from server) client_2, I have no response.
So, I try to specify an interface as ping source with -I.

# ping 192.168.7.3 -I eth1
bad interface address 'eth1'

Huh? Why? eth1 Device is correctly installed and its IP address
was correctly set by ifconfig. ifconfig shows it.
The same thing also happens with the other two ethernet cards,
eth0 and eth2...

However, client_1 can access to the internet using 192.168.7.1
as gateway, but client_2 seems to be absolutely out of the net!
I've find out many tutorials that "solve" my problem simply
setting up a bridge with brctl, but noone of these really work
with my network configuration. All of this tutorials start with
the rule "all clients can be reached with a simple ping by the
server".

So.. what can I do? Anyone can help me?
Note that ip_forward option was already set to "1".



Thanks in advance,
Odin_Eidolon