hi krishnan,
i think are confusing DSL with a leased line serial connection.
firstly for every DSL connection, if u started getting 4 addresses ( iam confused by what u mean by ur description of addresses here) then we would be out of stock of ip addresses in a day.
ur suggestion might be right , but i would like to modify it like this without ip forwarding,
|--------| ______|__ |--------| ISP | 1 | | | --------|WinBox | |LinuxBox| |__ ___2_| |________| | |----- To private network
in this case, the connection from ur isp goes to the usb port
A crossover cable connects the linux and the windows box.
A static route is added from the NIC 1 to the linux box with NIC 1 as the gateway for packets destined to the linux box.
The lan connects to the windows gateway through the 2nd NIC, and is seprated from the external network.
awaiting ur comments :)
regards, prem.