Hello

I would like to know how to setup ubuntu to access the internet through another pc by means of using 1 main network connected to a modem
and another small network without a modem.

i have done this in windows before without a problem but the same approach doesnt work with ubuntu

the way i got windows to do it was to have the "server" with 2 network cards
1 connected to the main network and the second connected to another pc
the second network card was configured to use the main network card as a gateway.
and the second pc would use the main pc as a gateway

how do i make this possible ?

sorry for the long post
Thanks in advance