Need help here .. The problem that i am having is when a client in subnet 172.18.0.0/24 which is added to ether3 tries to access the webserver which is also in ether3 in subnet 192.168.1.0/24 the webserver sees the client ip as 192.168.1.1 which is the ip added to ether3 interface. how can i make it forward the actual client ip which is the 172.18.0.0/24 subnet. thanks

Narrow down your masquerade rule so that it specifies the out interface of your WAN port.

that solved the problem .. thanks