> Will these packets pass through INPUT chains and go > out from OUT chains?and they are changed at the local process ? No, the INPUT and OUTPUT are chains *only* used by the local iptables machine. FORWARD is the chain used by PC's on your lan. > I am puzzled now . Did you look in the iptables tutorial (chapter 3) ? http://iptables-tutorial.frozentux.net/ There is an explanation with pic in it. Rob
