How to make linux the gateway computer?
 

I have a 4 port router with a Linux box and windows box.

I want all the windows traffic to go through the linux box so I set the windows box to a static IP with the IP of the linux box as its gateway, and I set IP forwarding on the linux box
(echo 1 > /proc/sys/net/ipv4/ip_forward)

When I attempt to visit a url on the windows box, I see (using ethereal) that the traffic goes to the linux box, but doesn't go out. (In ethereal, I do see ICMP messages from linux to windows saying destination unreachable)

Do I need to set an iptables rule to make this work?

refer this following link
http://www.yolinux.com/TUTORIALS/Lin...rkGateway.html